The antifertility and antinidation effects of three extracts (benzol, ethyl acetate and alcohol) of Cyathula Oficinalis Kuan on mice were observed. The results indicate that the benzol extract had significant antifertility action. Its effective rate of antifertility was 100%, when 250 mg/kg was given orally. As compared with control, when 250 mg/kg ethyl acetate extract was given, the rate of antifertility was 63.7%. If 500 mg/kg ethyl acetate extract was given the effective rate of antifertility increased over 90%. However, when 250～500 mg/kg alcohol extract was given, the rate of antifertility was only 40～54%. The study of antinidation showed that the benzol extract (500 mg/kg )could effectively prevent implatation. The rate of antinidation was 100%, and yet the ethyl acetate and alcohol extracts were 66.7% and 40% repectively. The results suggest that the three extracts of Cyathula Officinalis Kuan all had antifertility effect, but the action of benzol extract was more effective than other two extracts.

By means of chromalum-hematoxylin and thiosulfate aldehydefuchsin stains the magnocellular neurosecretory neuron of the rat hypothalamus was studied. The cell body of neuron containing various amounts of secretory granules was large in size, with a variety of shapes. The axon of neuron showed an beaded appearance; only one in each neuron was very fine in diameter and left hypothalamic nuclei to form the hypothalamo-neurohypophyseal tract. The dendrite, in general, thicker than the axon, did not project outside of the nucleus. Many of the thick short dendrites did not contain secretory granules or only few secretory granules. The thick processes with more secretory granules were considered as dendritic processes. A number of axons and thick processes containing secretory granules also contacted with the endothelium of vessels and the ependyma of the third ventricle. In addition, a group of magnocellular secretory neurons were found in the sub-choroid plexuses of the lateral ventricle.

By means of ABC immunoenzyme technique, the distribution of GnRH neurons and fibers in the brains of rats and mice was observed, The results showed that more than 90% of GnRH neuronal perikarya were concentrated in the diagonal band-medial preoptic area near the organum vasculosum lamina terminalis, extending rostro-dorsally to the medial septic nucleus and caudo-laterally to the supraoptic nucleus region. No GnRH cell body could be found in the mediobasal hypothalamus, GnRH fibers terminated in the median eminence via the periventricular and lateral tracts. In the rostral median eminence, fibers were present in its entire layers and width, and caudally separated into two laterally-located bundles. The difference of GnRH system between rodents and primates, as well as its significance in reproduction are discussed.

Observations of the ultrastructural changes in neurons of hypothalamie arcuate, supraoptic and paraventricular nuclei were carried out in the rats following gossypol treatment at a dosage of 30mg/kg/day for 5 weeks. The results showed that after gossypol treatment no marked changes in supraoptic and paraventricular cells could be seen at electron microscopic level, and that there appeared a series of ultrastrucrural changes reflecting increased neurosecretory activity in some of arcuate neurons.They were as follows: Golgi complex and rough endoplasmic reticulum were slightlydilated and filled with homogeneous, low electron density materials in their cisternae; the amounts of neurosecretory granules, lysosomes, nucleolus-like bodies, and microtubules were increased. The nature, significance and cause of these changes are discussed.

By means of histological and immunohistochemical methods,effects of a singleintraperitoneal injection of ethane dimethanesulphonate(EDS,75 mg/kg bodyweight)on the hypothalamo-pituitary-testicular axis of the rat were observed inthis study.Three days after administration of EDS,Leydig cells were eliminated;some LH cells in pituitary became larger or decreased in immunoreactivity;but nosignificant change could be found in hypothalamic GnRH system.Seven days afterEDS,degeneration of spermatogenic epithelium was marked,the staining intensity ofLH cells was generally reduced,the number of GnRH immunorcactive neurons inthe hypothalamus as well as the density and staining intensity of GnRH fibers andterminals in the median eminence were significantly diminished.Testosteronereplacement increased the number of late spcrmatids in testis and restored theabove-mentioned changes in the hypothalamus and pituitary.These results indicate that following administration of EDS,1)spermatogenesisdamage is resulted from destruction of Leydig cells and cessation of testosterone secretion;2)respective hormone release from hypothalamic GnRH system andpituitary LH cells is increased;3)loss of testosterone negative feedback is themajor factor responsible for the enhancement of secretory activity of the hypotha-lamo-pituitary axis;and that 4)EDS can be a useful experimental tool forstudying hypothalamo-pituitary-testiculer axis and intratesticular local regulation.

The synaptic organization of the sexually dimorphic nucleus of the preopticarea(SDN-POA)of male and female rats were examined with electron micro-scope.The results indicated that the synaptic pattern of SDN-POA showedsignificant sexual dimorphism:1.The numbers of total and shaft synapses whichoccupied the vast majority of total synapse were 2 times greater in male than infemale.2.The number of spine synapse of the female was 4.6 times greater thanthat of the male.3.In female,either the numbers of spine synapse with clear andmixed synaptic vesicles or the numbers of symmetrical and asymmetrical spinesynapses were markedly higher than in male.In contrast,the ratio of Gray Ⅱ toGray Ⅰ was 2.4 times larger in male than in female.4.The number of shaft synapsewith clear vesicle was greater in male than in female.In both sexes,however,thesignificant difference in the number of shaft synapse with mixed vesicle was notfound.5.There was no significant sexual difference in the number of asymmetricalshaft synapse,while the number of symmetrical shaft synapse was 2.7 times greaterin male than in female.

The cytoarchitecture of the sexually dimorphic nucleus of the preoptic area(SDN-POA)of male and female rats was studied with Nissl stain and rapid Golgimethod under light microscope.The results were as follows:1.The volume of theSDN-POA of the male was markedly 3.1 times larger than that of the female.2.In both sexes,the cell density of the SDN-POA significantly increased as comparedwith that of the surrounding,while the sexual difference of the cell density withinthe SDN-POA was not found.3.There was marked male-female difference in theneu(?)onal organization of the nucleus,in which the number of large cells was signi-ficantly greater in males than in females.4.In males,dendritic trees principallyoriented in dorsolateral,ventrolateral and medial directions.In contrast,dendritictrees in females mainly oriented in dorsal and ventromedial directions.5.The meantotal length of the dendritic tree was larger in males than in females and the dis-tribution of the dendritic tree showed sexual difference in the X axis but not in theY axis.6.The number of the dendritic spine was 2.1 times greater in females thanin males.

Gonadotropin-releasing hormone(GnRH)prohormone of human and rat consistsof GnRH and GnRH-associated peptide(GAP).In this study,three antisera againstN-terminal,mid-region and C-terminal of GAP,and ABC immunoenzyme methodwere used to observe the GAP neurons in the brains of the rat,mouse and guineapig.The distribution of GAP neurons in these animals was similar.GAP perikaryawere mainly present in the septo-preoptic area,with the largest concentration inthe diagonal band near the organum vasculosum of the lamina terminalis.SomeGAP perikarya were also seen in the brain area near the supraoptic nucleus.GAPfibers were widely present in the forebrain and hypothalamus,and terminated inthe organum vasculosum of lamina terminalis and median eminence.Of 3 GAP antisera,the one against N-terminal gave more immunoreactive elements and moreintense staining.The morphology and distribution of GAP perikarya,fibers andterminals were similar to those of GnRH.These results,combined with other relatedfacts,suggest that there is a common GnRH prohormone in mammals,and itsprocessing products,GAP(or cleavage fragments)and GnRH,are cosecreted intohypophysial portal system to regulate anterior pituitary hormone secretion.

The morphology of the GnRH neurons in the rat brain during postnatal development was studied quantitatively using the ABC immunostaining method and an image analyser. The pattern of distribution of the GnRH neurons in different ages animals used was similar. GnRH cells of rats aged 1-7 days were small in size with short processes, pale-stained, and smooth in outline The number of GnRH cells in 1 day rats was not significantly different from that of adult, but a significant decrease in the GnRH cell number appeared in 7 day rats. In postnatal day 14, Gn-RH neurons reached adult level in cell body size, number and staining intensity. The GnRH fibers and terminals in the median eminence were gradually increased and reached adult level up to 14 postnatal days. These results suggested that the number of GnRH neurons is determined shortly after birth; the second postnatal week is the critical period for the development of GnRH neuronal morphology; and the establishment of function of the GnRH neuronal system may be earlier than its morphological maturation.

The distribution relationships of gonadotropin-releasing hormone (GnRH) (5-HT), tyrosine hydroxylase (TH), neurophysin (NP) and ?-endorphin (?-END) in the diagonal band of Broca (DBB) of rat brain were studied by immunohis- tochemistry. The results indicate that there was a close spatial overlap in the distribution between 5HT,TH,NP,?-END fibers and GnRH perikarya and fibers in the ventromedial area of VDBB and dorsomedial area of HDBB. In the dorsomedial area of VDBB close overlap in the distribution between 5-HT fibers and GnRH neurons was also observed. In addition, some TH and NP immunoreactive neurons were found in the medial areas of VDBB and HDBB, The close relationships in distribution and functional significance of GnRH,5-HT, TH, NP and ?-END were discussed.