To establish an HPLC method for determining components in monocrotalinum liposomes. The results showed a good linear relationship in monocrotalinum liposomes within the concentration range between 1.6-102.4 mg x L(-1) (r = 0.999 8), with RSDs of intra-day precision, inter-day precision, stability and reproducibility of 0.61%, 0.92%, 1.7%, 1.6%, respectively. The recovery rate of monocrotaline was (99.96 +/- 0.50)%. These data indicated that the HPLC method could accurately determine components in monocrotalinum liposomes. Meanwhile, the microcolumn centrifugation method was established to determine the entrapment efficiency of components in monocrotalinum liposomes. As a result, the recovery rate and the blank liposome recovery of free components were (94.44 +/- 0.77)%, (95.86 +/- 0.68 )%, respectively. According to the parallel determination of the entrapment efficiency of three monocrotaline liposomes, their RSD was 4.0%. The data indicated that the microcolumn centrifugation method was an accurate and feasible method for determining the entrapment efficiency of monocrotaline liposomes.
Chromatography, High Pressure Liquid ; methods ; Drug Carriers ; chemistry ; Drug Compounding ; Liposomes ; chemistry ; Monocrotaline ; chemistry

Animals ; Hypertension, Pulmonary ; chemically induced ; physiopathology ; Monocrotaline ; adverse effects ; Rats ; Rats, Sprague-Dawley ; Thrombomodulin ; metabolism

OBJECTIVETo investigate the fetotoxicity of monocrotaline.

METHODMouse whole embryo culture (WEC) was applied. Post-implantation (8.5 d) mouse embryos were isolated from their mothers and put into the medium of immediately centrifuged serum (ICS) prepared from rats. Different concentrations of monocrotaline (100, 50, 25, 12.5 mg x L(-1)) were added into the WEC. Development (yolk sac diameter, crown-rump length, head length, somite number) and organic morphodifferentiation (yolk sac circulation, allantois, embryonic flexion, heart, brain, optic-otic-olfactory organ, branchial arch, maxillary, mandible, bud) of embryos were observed at 48 h after treatment.

RESULTObvious fetotoxicity could be observed in various monocrotaline treatment groups in a dose-dependent manner. Development of embryos was delayed significantly at dose 12.5-100 mg x L(-1). Malformations were shown in all organic morphodifferentiation indice, especially in opti-otic organ, mandible and bud.

CONCLUSIONMonocrotaline had obvious fetotoxicity in vitro WEC, indicating that exposure of pregnant mice to monocrotaline may have potential risk on fetus.

Animals ; Cell Differentiation ; drug effects ; Culture Media ; Embryo, Mammalian ; drug effects ; physiology ; Female ; Male ; Mice ; Monocrotaline ; toxicity

OBJECTIVETo observe the pathological changes in the myocardial and pulmonary tissues in miniature pigs with chronic pulmonary hypertension induced by monocrotaline (MCT).

METHODSTwelve male miniature pigs (weigh 15.0-18.0 kg, aged 4.0-4.5 months) were examined for baseline mean pulmonary artery pressure (mPAP), followed by intraperitoneal injection of 10.0 mg/kg MCT in 10 randomly selected pigs. The mean pulmonary artery pressure at 4 and 8 weeks were determined, and the pathological changes in the myocardial and pulmonary tissues were observed.

RESULTSThe baseline mPAP of normal miniature pigs was 15.19∓0.70 mmHg. At 4 and 8 weeks after MCT injection, the sPAP and dPAP were 19.69∓2.47 mmHg and 25.62∓4.88 mmHg, respectively, and the mPAP increased significantly compared with that of the normal control group (P<0.01). Obvious pathological changes such as pulmonary hypertension and right ventricular hypertrophy were found in the pigs 4 weeks after MCT injection, and at 8 weeks, significant pathological changes occurred including right ventricular fibrosis and thickening of the tunica media of the pulmonary artery.

CONCLUSIONMCT can cause pulmonary hypertension in miniature pigs 8 weeks after drug administration, shown as increased pulmonary artery pressure and pulmonary vascular remodeling.

Animals ; Hypertension, Pulmonary ; chemically induced ; pathology ; Lung ; pathology ; Male ; Monocrotaline ; adverse effects ; Myocardium ; pathology ; Swine ; Swine, Miniature

OBJECTIVE: To study the protective effects of ginkgo biloba extract on the right ventricular hypertrophy. METHODS: Seventy-two SD male rats were randomly divided into 3 groups: control group(CON), monocrotaline-induced right ventricular hypertrophy group (MCT) and ginkgo biloba extract treated group (EGB) (n=24 in each group). Group MCT and group EGB were intraperitoneally injected with 2%MCT at the dose of 60 mg /kg on the first day. From the second day, group MCT was injected with 2 ml 0.9% sodium chloride, and 60 mg/kg ginkgo leaf extract was administered to the stomach in group EGB. The control group was injected with 2 ml 0.9% sodium chloride on the first day. After 3 weeks, in each group,cardiac hemodynamic changes were measured, heart weight index was calculated, and myocardial pathological changes were observed by HE staining. The expression of TRPC6 was detected by real-time polymerase chain reaction (real-time -PCR) and Western blot. RESULTS: Compared with the control group, the right ventricular systolic pressure (RVSP) was increased significantly in the MCT group(P＜0.01), the maximum or decline rate of descent (RV ±dp/dt) of the right ventricle pressure was increased significantly(P＜0.01), while the EGB group had the same trend as all the indexes in the group MCT, but the amplitude of all indicators in group EGB were decreased significantly than those of group MCT(P＜0.01), and the right ventricular hypertrophy index (RVMI) in group EGB was significantly lower than that in group MCT(P＜0.01).Group MCT showed typical myocardial hypertrophy performance by HE staining, and the right ventricular myocytes in group EGB were significantly improved than that in group MCT, and the mRNA and protein expression levels of TRPC6 in the right ventricle of group MCT and group EGB were increased(P＜0.01), while the EGB group was significantly lower than that of the MCT group(P＜0.01). CONCLUSION Ginkgo biloba extract may inhibit the signal pathway of CaN / NFAT in cardiac myocytes by reducing the expression of TRPC6 protein, and then play an early protective effect on myocardial hypertrophy.
Animals ; Hypertrophy, Right Ventricular ; chemically induced ; drug therapy ; Male ; Monocrotaline ; Plant Extracts ; pharmacology ; Random Allocation ; Rats ; Rats, Sprague-Dawley

The pathophysiological implications of aldosterone and adrenomedullin in the cardiac ventricular hypertrophy were examined. Male Sprague-Dawley rats were treated with deoxycorticosterone acetate (DOCA)-salt and monocrotaline (MCT) to selectively elicit left and right ventricular (LV, RV) hypertrophy, respectively. The mRNA expression of aldosterone synthase and adrenomedullin in LV and RV was determined by reverse transcription-polymerase chain reaction. The expression of aldosterone synthase and adrenomedullin was increased in LV, while not altered significantly in RV of DOCA-salt-treated rats. On the contrary, the expression was not significantly altered in LV, but increased in RV of MCT-treated rats. The enhanced expression of aldosterone synthase may be causally related with the development of ventricular hypertrophy, and the increased expression of adrenomedullin may act as a counter-regulatory mechanism.
Adrenomedullin* ; Aldosterone Synthase* ; Aldosterone* ; Animals ; Desoxycorticosterone ; Humans ; Hypertrophy ; Hypertrophy, Right Ventricular* ; Male ; Monocrotaline ; Rats* ; Rats, Sprague-Dawley ; RNA, Messenger

The present study was aimed to explore pathophysiological implications of nitric oxide in the development of left and right ventricular hypertrophy. To induce selective left and right ventricular hypertrophy, rats were made two-kidney, one clip (2K1C) hypertensive and treated with monocrotaline (MCT), respectively. Six weeks later, the hearts were taken and their ventricular tissue mRNA and protein expression of endothelial constitutive isoform of nitric oxide synthase (NOS) were determined by reverse transcription-polymerase chain reaction and Western blot analysis, respectively. In 2K1C hypertensive rats, the expression of NOS mRNA was increased in parallel with its proteins in the left ventricle, but not in the right ventricle. In MCT-treated rats, the expression of NOS mRNA and proteins were proportionally increased in the right ventricle, but not in the left ventricle. These results suggest that the expression of NOS is specifically increased in association with the ventricular hypertrophy, which may be a mechanism counteracting the hypertrophy.
Animals ; Blotting, Western ; Cardiomegaly ; Heart ; Heart Ventricles ; Hypertrophy ; Hypertrophy, Right Ventricular* ; Monocrotaline ; Nitric Oxide Synthase ; Nitric Oxide* ; Rats ; RNA, Messenger

PURPOSE: To examine the effect of bosentan, a dual endothelin receptor (ER) antagonist, on the development of monocrotaline (MCT)-induced pulmonary hypertension in rats by especially focusing on the pulmonary vascular morphology changes. METHODS: Sprague-Dawley rats were treated as follows: controls received a subcutaneous saline injection, MCT-treated rats received a subcutaneous MCT injection, and bosentan-treated rats received a MCT injection followed by treatment with bosentan (20 mg/kg/day). To assess the effects of ER blockade on the time course, the animals were exsanguinated, and their hearts and lungs were dissected after 7, 14, or 28 days. RESULTS: The mean body weights of the MCT- and bosentan-treated rats were significantly lower than that of the control rats on days 7, 14, and 28. Bosentan administration significantly inhibited the progression of right ventricular hypertrophy on day 28 (right ventricle/[left ventricle+septum]: 0.71+/-0.10 in MCT-treated rats vs. 0.49+/-0.09 in bosentan-treated rats; P<0.05). Quantitative analysis of peripheral pulmonary arteries revealed that the increase in medial wall thickness after MCT injection was significantly attenuated in the bosentan-treated rats on day 28 (49.96+/-10.06% in MCT-treated rats vs. 47.09+/-10.48% in bosentan-treated rats; P<0.05). In addition, the increase in the number of intra-acinar muscular arteries after MCT injection was reduced by bosentan on days 14 and 28. CONCLUSION: Bosentan administration in intermediate doses exerts inhibitory effects on lung vascular hypertrophy and right ventricular hypertrophy during the development of MCT-induced pulmonary hypertension in rats.
Animals ; Arteries ; Body Weight ; Endothelins ; Heart ; Hypertension, Pulmonary ; Hypertrophy ; Hypertrophy, Right Ventricular ; Lung ; Monocrotaline ; Pulmonary Artery ; Rats ; Rats, Sprague-Dawley ; Receptors, Endothelin ; Sulfonamides

BACKGROUND AND OBJECTIVES: Endothelin (ET)-1, a potent endothelium-derived vasoconstrictor peptide, has a potential pathophysiologic role in pulmonary hypertension. Bosentan, a dual ET receptor (ET(A)/ET(B)) antagonist, is efficacious in treatment of pulmonary hypertension. The objectives of this study were to investigate the expression of ET-1 and ET receptor A (ERA) genes and to evaluate the effect of bosentan in monocrotaline (MCT)-induced pulmonary hypertension. MATERIALS AND METHODS: Four-week-old male Sprague-Dawley rats were treated as follows: control (n=36), subcutaneous (sc) injection of saline; MCT (n=36), sc injection of MCT (60 mg/kg); and bosentan (n=36), sc injection of MCT (60 mg/kg) plus 25 mg/kg/day bosentan orally. RESULTS: Serum ET-1 concentrations in the MCT group were higher than the control group on day 28 and 42. Quantitative analysis of peripheral pulmonary arteries revealed that the increase in medial wall thickness after MCT injection was significantly attenuated in the bosentan group on day 28 and 42. In addition, the increase in the number of intra-acinar muscular arteries after MCT injection was reduced by bosentan on day 14, 28 and 42. The levels of ET-1 and ERA gene expression were significantly increased in the MCT group compared with control group on day 5, and bosentan decreased the expression of ET-1 on day 5. CONCLUSION: ET-1 contributes to the progression of cardiopulmonary pathology in rats with MCT-induced pulmonary hypertension. Administration of bosentan reduced ET-1 gene expression in MCT-induced pulmonary hypertension in rats.
Animals ; Arteries ; Endothelin-1 ; Endothelins ; Gene Expression ; Humans ; Hypertension, Pulmonary ; Male ; Monocrotaline ; Pulmonary Artery ; Rats ; Rats, Sprague-Dawley ; Receptors, Endothelin ; Sulfonamides

OBJECTIVEPulmonary hypertension is a proliferative vascular disease characterized by pulmonary vascular structural remodeling. Until now, the pathogenesis of pulmonary hypertension is still not fully understood. Although considerable progress has been made, there is, to date, no cure for advanced pulmonary vascular disease. Recently, a number of studies suggest that endogenous vascular elastase (EVE) play a role in the vascular changes associated with pulmonary hypertension. The purpose of the study was to determine whether an elastase inhibitor might reverse advanced pulmonary vascular disease produced in rats by injection of monocrotaline.

METHODSOne hundred and twenty male Sprague-Dawley rats were used in this study. The rats were divided into three groups: control, model and ZD-0892 groups. In the model and ZD-0892 groups, the rats were subjected to a single subcutaneous injection of monocrotaline (60 mg/kg) in the hind flank, while the rats in control group received an equivalent volume of 0.9% saline. From day 21, the rats in the ZD-0892 and model groups received twice-daily gavage tube feedings of either ZD-0892 at a dose of 240 mg/kg per day or its administration vehicle, while the rats in control group were subjected to an equivalent volume of 0.9% saline. On days 21, 28 and 35 post-injection, the elastolytic activity was measured with a fluorescence microplate reader and pulmonary artery pressure was detected via catheterization. Meanwhile, the lungs were evaluated morphologically, using the barium-gelatin perfusion technique.

RESULTSThe injection of monocrotaline led to severe pulmonary hypertension in rats 21 days later and pulmonary artery elastolytic activity increased remarkably. A 1-week treatment with ZD-0892 resulted in declines in elastase activity. This was associated with significant declines in pulmonary artery pressure, decreases in muscularization of peripheral arteries and reductions in medial hypertrophy. After 2 weeks, elastase activity returned to normal level. Pulmonary artery pressure and structure were normalized.

CONCLUSIONIncreased elastase activity is important in the development of vascular changes and progressive pulmonary hypertension. ZD-0892 can suppress the elastase activity and completely reverse the fatal pulmonary hypertension induced by monocrotaline in rats.

Animals ; Hypertension, Pulmonary ; chemically induced ; drug therapy ; Male ; Monocrotaline ; toxicity ; Pancreatic Elastase ; antagonists & inhibitors ; Pulmonary Artery ; drug effects ; pathology ; physiopathology ; Pyrroles ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Sulfonamides ; pharmacology