Prolactin is a polypeptide hormone which mainly acts on the reproductive system and plays an important role in penile erection and ejaculation. Prolactin receptors have a variety of short forms apart from the classic long form, which are widely expressed in male reproductive glands. High levels of prolactin can induce erectile dysfunction and results in secondary male infertility, which are mainly associated with the inhibition of dopaminergic activity, reduction of the testosterone level, and contraction of the cavernous smooth muscle. Moreover, low levels of prolactin can result in ejaculatory dysfunction. This article updates the views on the expressions of prolactin receptors in the male reproductive system, the effects of prolactin on penile erection and ejaculation, and its action mechanisms.
Ejaculation ; physiology ; Erectile Dysfunction ; Humans ; Infertility, Male ; Male ; Muscle, Smooth ; physiopathology ; Penile Erection ; physiology ; Prolactin ; physiology ; Receptors, Prolactin ; physiology ; Reproduction

The aim of this study is to evaluate pituitary-ovarian function at different postpartum periods during the lactational amenorrhea in order to understand the mechanism by which puerperal lactation is associated with a protracted period of amenorrhea and natural infertility. Ninety four lactating women and 119 lactating women with menstruation, aged between 21 and 38 years, volunteered for this study. The pituitary was relatively insensitive to LH-RH during the first 3 weeks following delivery. The recovery of FSH responsiveness to LH-RH occurred earlier than that of LH. Normal FSH response resumed in the 2nd week while the LH response, although not normal, started at the 3rd week postpartum. Pituitary responsiveness after the 5th week postpartum was similar to that occurring in normally menstruating women, except that FSH response was exagerated. Serum prolactin levels were elevated above 160 ng/ml until the 5th week postpartum and decreased to 84.2 ng/ml in the 6th week postpartum. It appears that at least one reason for anovulation during the first four weeks following delivery is the relative insensitivity of the pituitary to hypothalamic stimulation. Prolactin does not seem to modulate pituitary responsiveness to LH-RH. In order to clarify hormonal profiles during the lactational amenorrhea beyond the 5th week puerperium, serum levels of LH, FSH, prolactin, estradiol and progesterone were determined during different postpartum periods. Serum FSH and LH levels during 1-10 months postpartum were similar to basal levels seen during the normal menstrual cycle. Serum estradiol concentrations throughout 1-10 months postpartum, however, were significantly decreased as compared with the levels during the follicular phase of the normal menstrual cycle. Serum prolactin levels were elevated throughout 1-10 months postpartum in lactating amenorrhic women but decreased as the postpartum period lengthened. As compared with lactating amenorrhic women, lactating women with resumed menstruation showed a decrease in prolactin levels from 89.20 ng/ml to 51.39 ng/ml at 1-3 months, from 75.08 ng/ml to 49.99 ng/ml at 4-6 months, and from 54.73 ng/ml to 28.74ng/ml at 7-10 months postpartum. These results suggest that the apparent anovulation seen beyond 5th week postpartum during lactation was not due to pituitary insensitivity to LH-RH. Rather, prolactindependent mechanism interfering with cyclic activity may be operative during long term lactation.
Amenorrhea/etiology* ; Female ; Gonadorelin/pharmacology ; Gonadotropins, Pituitary/secretion ; Human ; Lactation* ; Ovary/physiology* ; Pituitary Gland/physiology* ; Pregnancy ; Prolactin/physiology ; Puerperium*

In our previous study, we demonstrated that immobilization stress blocked estrogen-induced luteinizing hormone(LH) surge possibly by inhibiting the synthesis and release of gonadotropin-releasing hormone (GnRH) at the hypothalamic level and by blocking estrogen-induced prolactin (PRL) surge by increasing the synthesis of dopamine receptor at the pituitary level in ovariectomized rats. The present study was performed to determine whether immobilization stress affects pituitary LH responsiveness to GnRH, and whether endogenous opioid peptide (EOP) and dopamine systems are involved in blocking LH and PRL surges during immobilization stress. Immobilization stress was found to inhibit basal LH release and to completely abolish LH surge. However, the intravenous application of GnRH agonist completely restored immobilization-blocked LH surge and basal LH release. Treatment with naloxone did not exert any effect on immobilization-blocked LH surge but increased basal LH release during immobilization stress. Pimozide did not affect immobilization-blocked LH surge or basal LH release. Naloxone also decreased immobilization-induced basal PRL release, but had no effect on immobilization-blocked PRL surge. Immobilization-increased basal PRL levels were augmented by pimozide treatment and immobilization-blocked PRL surge was dramatically restored by pimozide. We conclude that immobilization stress does not impair pituitary LH response to GnRH, and that the immobilization stress-induced blockage of LH surge is probably not mediated by either the opioidergic or the dopaminergic system. However, immobilization-blockade of PRL surge may be partly mediated by the dopaminergic system.
Animal ; Estradiol/*pharmacology ; Female ; Gonadorelin/*pharmacology ; Immobilization ; Luteinizing Hormone/*secretion ; Naloxone/pharmacology ; Opioid Peptides/physiology ; Ovariectomy ; Prolactin/*secretion ; Rats ; Rats, Sprague-Dawley ; Receptors, Dopamine/physiology ; Stress/*metabolism

BACKGROUND: Recent discoveries on the physiology of an erection have demonstrated that the organic causes of impotence are more common, and psychogenic impotence is correspondingly less common than was formally believed. The incidence of sexual dysfunctions in chronic obstructive pulmonary disease (COPD) patients is largely unknown or may be perfunctorily attributed to the associated illness or to aging. This study investigated whether or not the impotence was related to the COPD itself as well as whether or not it may stem from organic causes in a notable proportion of such patients. METHODS: The sexual function was evaluated in 10 COPD patients and 10 normal control subjects. A nocturnal Rigi Scan was performed to evaluate the erectile function of each group. The level of hormones such as the free testosterone, prolactin and thyroid stimulating hormone (TSH) was measured, and a pulmonary function test and arterial blood gas analysis was performed. RESULTS: The time duration and frequency of a penile erection were significantly lower in COPD patients than the controls (p<0.05). In addition, the PaO2 levels correlated with the time duration of the penile erection. CONCLUSION: These results suggest that COPD is one of the causes of organic erectile dysfunction.
Aging ; Blood Gas Analysis ; Erectile Dysfunction* ; Humans ; Incidence ; Male ; Penile Erection ; Physiology ; Prolactin ; Pulmonary Disease, Chronic Obstructive* ; Respiratory Function Tests ; Testosterone ; Thyrotropin

OBJECTIVETo explore the efficacy of Tuina for postpartum lactation and work out a optimal protocol involved.

METHODSWith a randomized, controlled and clinical method, 84 primiparas were divided into a Tuina group and a control group. While patients in the control group received rooming-in conventional managements, those in the Tuina group were additionally treated with Tuina, including local manipulations on breasts combined with acupoint manipulations. The colostrum-time, lactation quantity and prolactin were observed to make the comparisons between two groups.

RESULTSThe scores of lactation quantity after 1th, 2nd, 3rd of the treatment were 1.660 +/- 0.785, 2.530 +/- 1.030, 2.880 +/- 1.171 in Tuina group and 1.270 +/- 0.533, 1.460 +/- 0.811, 1.500 +/- 0.583 in control group respectively, where there were significant differences in each time stage between two groups (all P < 0.001). The time of colostrum was (21.6 6 +/- 10.508) h in the Tuina group and (22.5 +/- 9.762) h in the control group, in which the difference was not statistically significant (P > 0.05). The levels of prolactin (314.35 +/- 110.37) ng/mL and (321.56 +/- 109.61) ng/mL in Tuina group, (385.78 +/- 85.19) ng/mL and (340.12 +/- 103.10) ng/mL in control group before and after treatment, there were no significant differences (both P > 0.05).

CONCLUSIONPostpartum Tuina on breasts could increase the quantity of lactation and delay the decreasing of the levels of prolactin, which contributes primiparas to lactate more and sooner.

Adult ; Amobarbital ; Breast ; secretion ; Breast Feeding ; Colostrum ; secretion ; Drug Combinations ; Female ; Humans ; Lactation ; Milk, Human ; secretion ; Postpartum Period ; physiology ; Prolactin ; metabolism ; Secobarbital ; Young Adult

AIMTo determine the exact roles of prolactin (PRL) in the pathogenesis of rheumatoid arthritis (RA) and supply experimental basis for clinical treatment of RA, and to investigate the expression of matrix metalloproteinase-9 (MMP-9) in the synovium of adjuvant arthritis rats.

METHODSForty rats were divided into four groups (n = 10): (1) Normal control group (group A); (2) Adjuvant arthritis control group (group B); (3) Hyperprolactinemic adjuvant arthritis group (group C); (4) Hypoprolactinemic adjuvant arthritis group (group D). The content of PRL in the serum was detected by radio-immunoassay method. The activity of MMP-9 was analyzed by gelatin zymography. The alteration of MMP-9 immunoreactivity were investigated by means of immunohistochemistry in the synovium of all groups. The expressions of MMP-9 were investigated by Western blot in the synovium of all groups.

RESULTSCompared with group A, the activity and expression of MMP-9 of group B in the synovium were highly increased. The activity and expression of MMP-9 in the synovium were the most distinctive in group C. Compared with group B, the activity and expression of MMP-9 in the synovium were decreased in group D, but still higher than group A.

CONCLUSIONThe present results indicated that PRL might involved in the pathogenesis of RA by regulating the secretion of MMP-9 in the synovium.

Animals ; Arthritis, Experimental ; metabolism ; Arthritis, Rheumatoid ; physiopathology ; Male ; Matrix Metalloproteinase 9 ; genetics ; metabolism ; Prolactin ; blood ; physiology ; Random Allocation ; Rats ; Rats, Wistar ; Synovial Membrane ; metabolism

AIMSpermatogenic dysfunction may result from thickening of seminiferous tubular basement membrane (BM) with tubular sclerosis. Transforming growth factor beta1 (TGF-beta1) plays an important role in fibrogenesis. The intracellular and extracellular expression of TGF-beta1 in the testis were immunohistochemically determined, using LC antibody (LC) for intracellular TGF-beta1 and CC antibody (CC) for extracellular TGF-beta1.

METHODSTwenty-three testicular biopsy specimens were obtained from varicocele and five from Sertoli-cell-only (SCO) patients, and five from normal volunteers. The relative area involved by the expression of TGF-beta1 for CC or LC (TGF-beta1 index for CC or LC) was examined, and semen parameters and serum hormonal levels and TGF-beta1 were analyzed. The Johnson score (JS), the BM thickness, and the tubular diameter were also determined.

RESULTSImmunoreactivity for CC was hardly detected. That for LC was detected in the Sertoli and germ cells. The TGF-beta1 index for LC was significantly higher in the varicoceles than in the normal testes. Interestingly, that for LC was significantly higher in the varicoceles than in the SCO. The level of serum TGF-beta1 was significantly higher in varicoceles than in the normal testes.

CONCLUSIONThe distribution of the intracellular and extracellular expression of TGF-beta1 in human testis was demonstrated. It suggests that TGF-beta1 is related to fibrosis of seminiferous tubules and may lead to spermatogenic disruption.

Adult ; Biopsy ; Estrogens ; blood ; Follicle Stimulating Hormone ; blood ; Humans ; Luteinizing Hormone ; blood ; Male ; Prolactin ; blood ; Reference Values ; Sertoli Cells ; physiology ; Spermatogenesis ; physiology ; Testis ; cytology ; pathology ; physiology ; Testosterone ; blood ; Transforming Growth Factor beta ; blood ; metabolism ; Varicocele ; blood ; physiopathology

OBJECTIVETo observe the influence of acupuncture on embryo implantation in rat model of embryo implantation dysfunction, and to primarily explore its possible mechanisms.

METHODSPregnant rats were randomly allocated into the control group, the model group and the acupuncture group. The pregnancy rate and average number of blastocyst were observed, the serum levels of estrodiol (E2), progesterone (P4) and prolactin (PRL) were detected by RIA, and the protein and mRNA expression of progesterone receptor (PR) and prolactin receptor (PRLR) in endometrial tissue of implantation site were determined using immunohistochemical assay and RT-PCR respectively.

RESULTSThe pregnancy rate and average number of blastocyst were significantly higher in the acupuncture group than those in the control group respectively (P <0.01). The serum levels of P4 and PRL as well as the protein and mRNA expression levels of PR and PRLR in the model group were significantly lower than those in the other two groups (P<0.05).

CONCLUSIONAcupuncture can promote embryo implantation in rats to a certain degree, and its mechanism might be related with the effects of acupuncture in mediating the sexual hormone levels and the receptor expression of rats.

Acupuncture Therapy ; Animals ; Embryo Implantation ; physiology ; Embryonic Development ; physiology ; Estradiol ; blood ; Female ; Immunohistochemistry ; Male ; Pregnancy ; Progesterone ; blood ; RNA, Messenger ; genetics ; metabolism ; Radioimmunoassay ; Random Allocation ; Rats ; Rats, Wistar ; Receptors, Progesterone ; biosynthesis ; genetics ; Receptors, Prolactin ; biosynthesis ; genetics ; Reverse Transcriptase Polymerase Chain Reaction

The novel coronavirus disease (COVID-19) pandemic is emerging as a global health threat and shows a higher risk for men than women. Thus far, the studies on andrological consequences of COVID-19 are limited. To ascertain the consequences of COVID-19 on sperm parameters after recovery, we recruited 41 reproductive-aged male patients who had recovered from COVID-19, and analyzed their semen parameters and serum sex hormones at a median time of 56 days after hospital discharge. For longitudinal analysis, a second sampling was obtained from 22 of the 41 patients after a median time interval of 29 days from first sampling. Compared with controls who had not suffered from COVID-19, the total sperm count, sperm concentration, and percentages of motile and progressively motile spermatozoa in the patients were significantly lower at first sampling, while sperm vitality and morphology were not affected. The total sperm count, sperm concentration, and number of motile spermatozoa per ejaculate were significantly increased and the percentage of morphologically abnormal sperm was reduced at the second sampling compared with those at first in the 22 patients examined. Though there were higher prolactin and lower progesterone levels in patients at first sampling than those in controls, no significant alterations were detected for any sex hormones examined over time following COVID-19 recovery in the 22 patients. Although it should be interpreted carefully, these findings indicate an adverse but potentially reversible consequence of COVID-19 on sperm quality.
Adult ; Asthenozoospermia/virology* ; COVID-19/physiopathology* ; China ; Gonadal Steroid Hormones/blood* ; Humans ; Male ; Progesterone/blood* ; Prolactin/blood* ; SARS-CoV-2 ; Semen/physiology* ; Semen Analysis ; Sperm Count ; Sperm Motility ; Spermatozoa/physiology* ; Time Factors

A clinicostatistical analysis of 683 males with infertility who visited the Pusan National University Hospital between January 1986 and December 1995 was performed. We divided the patients into 5 groups by Shirataki classification as follows, group I, sperm concentration above 20 x 106/ml, group II, oligozoospermia with a sperm concentration above 10 x 100000/ml, but below 20 x 1000000/ml, group III,oligozoospermia with a sperm concentration below 10x 100000/ml, group IV, primary azoospermia, group V, obstructive azoospermia. The mean age was 33.1 years. The mean duration of infertility was 48.2 months. The frequency in each groups were group IV 383 cases (56.1%), group III 127 cases (18.6%), group I 111 cases (16.3%), group II 37 cases (5.4%), and group V 25 cases (3.7%), respectively. Except group V, as decreasing the sperm density, testicular volume tended to reduce (p<0.01). The semen volume in group V was significantly less than that in other groups (p<0.05). As sperm density decreased, the sperm motility tended to reduce (p<0.05). The levels of serum luteinizing hormone (LH) and follicular stimulating hormone (FSH) in group IV were significantly the higher than other groups (p<0.05). As for serum prolactin and testosterone, there were no significant differences between each 5 group. Of etiologic factors of male infertility, idiopathic was the most common cause with 489 cases (71. 6%), and followed by varicocele 71 cases (10.4%), seminal tract obstruction 44 cases (6.4%), chromosome abnormality 30 cases (4.4%), infection 20 cases (2.9%), testicular trauma 13 cases (1.9%), cryptorchidism 10 cases (1.5%), hyperprolactinemia 4 cases (0.6%) and retrograde ejaculation 2 cases (0.3%). A total of 391 cases had a management for male infertility which consisted of medical treatments 291 cases (74.4%), surgical treatments 89 cases (22.8%) and assisted reproductive technologies 11 cases (2.8%). In conclusion, We think the more clear clarification of physiology of male reproductive system, the development of new drugs for the improvement of spermatogenesis and the application of advanced assisted reproductive technique would be needed to handle properly the patients with male infertility.
Azoospermia ; Busan ; Chromosome Aberrations ; Classification ; Cryptorchidism ; Ejaculation ; Humans ; Hyperprolactinemia ; Infertility ; Infertility, Male* ; Luteinizing Hormone ; Male ; Male* ; Oligospermia ; Physiology ; Prolactin ; Reproductive Techniques, Assisted ; Semen ; Sperm Motility ; Spermatogenesis ; Spermatozoa ; Testosterone ; Varicocele