Arvanil, anandamide and N-arachidonoyl-dopamine (NADA) inhibit emesis through cannabinoid CB1 and vanilloid TRPV1 receptors in the ferret.

Cannabinoid (CB) agonists suppress nausea and vomiting (emesis). Similarly, transient receptor potential vanilloid-1 (TRPV1) receptor agonists are anti-emetic. Arvanil, N-(3-methoxy-4-hydroxy-benzyl)-arachidonamide, is a synthetic 'hybrid' agonist of CB1 and TRPV1 receptors. Anandamide and N-arachidonoyl-dopamine (NADA) are endogenous agonists at both these receptors. We investigated if arvanil, NADA and anandamide were anti-emetic in the ferret and their mechanism of action. All compounds reduced the episodes of emesis in response to morphine 6 glucuronide. These effects were attenuated by AM251, a CB1 antagonist that was pro-emetic per se, and TRPV1 antagonists iodoresiniferatoxin and AMG 9810, which were without pro-emetic effects. Similar sensitivity to arvanil and NADA was found for prodromal signs of emesis. We analysed the distribution of TRPV1 receptors in the ferret brainstem and, for comparison, the co-localization of CB1 and TRPV1 receptors in the mouse brainstem. TRPV1 immunoreactivity was largely restricted to the nucleus of the solitary tract of the ferret, with faint labeling in the dorsal motor nucleus of the vagus and sparse distribution in the area postrema. A similar distribution of TRPV1, and its extensive co-localization with CB1, was observed in the mouse. Our findings suggest that CB1 and TRPV1 receptors in the brainstem play a major role in the control of emesis by agonists of these two receptors. While there appears to be an endogenous 'tone' of CB1 receptors inhibiting emesis, this does not seem to be the case for TRPV1 receptors, indicating that endogenously released endocannabinoids/endovanilloids inhibit emesis preferentially via CB1 receptors.

The expression and role of Fas ligand in intestinal inflammation.

Fas ligand (FasL) is involved in the pathogenesis of inflammatory diseases and immune privilege. We examined the expression of FasL in the enteric nervous system (ENS) in murine colitis and guinea-pig ileitis. We studied FasL immunoreactivity, functional integrity of the ENS, severity of colitis, and distribution of neutrophils in wild type and B6/gld mice that lack functional FasL. In ileitis, the distribution of FasL, CD4+ and CD8+ T cells was examined. FasL expression was increased in the ENS of wild type mice with colitis, but decreased labelling of nerve fibres was noted in B6/gld mice. Neutrophils were more abundant and widely distributed in B6/gld mice. Colitis was more severe and persistent in B6/gld mice 7 days after induction. Functional parameters of intestinal secretion and motility in B6/gld mice were the same as controls. In ileitis, FasL expression was increased in the guinea-pig ENS and returned to control levels following the resolution of inflammation. While T cells were not present in the ENS of controls, they were observed during inflammation, but were excluded from ganglia. The number of enteric neurons was unchanged over the course of inflammation. The expression of FasL is altered in intestinal inflammation and contributes to its resolution in experimental colitis.

Cannabinoids inhibit emesis through CB1 receptors in the brainstem of the ferret.

BACKGROUND & AIMS: Marijuana and other cannabinoids are effective anti-emetics. Despite ongoing controversy over their usage, the receptor distribution and the site of the anti-emetic action of these compounds are not known. Our aim was to investigate whether the cannabinoid 1 receptor (CB1r) and endocannabinoids play a role in the anti-emetic action of cannabinoids. METHODS: Ferrets were given an emetic stimulus and the number of episodes of retching and vomiting were observed after administration of CB1r agonists and a CB1r antagonist. CB1r and fatty acid amide hydrolase (FAAH), which degrades endocannabinoids, were localized by immunohistochemistry. RESULTS: CB1r and FAAH were localized in the dorsal vagal complex, consisting of the area postrema, nucleus of the solitary tract, and the dorsal motor nucleus of the vagus in the brainstem. CB1r was found in the myenteric plexus of the stomach and duodenum. Activation of CB1r by the agonists (delta)(9)-tetrahydrocannabinol, WIN 55,212-2, and methanandamide inhibited emesis and their action was reversed by a selective CB1r antagonist, which alone had no effect, but potentiated vomiting in response to an emetic stimulus. CONCLUSIONS: CB1r mediates the anti-emetic action of cannabinoids in the dorsal vagal complex. Endocannabinoids are a novel neuroregulatory system involved in the control of emesis.

Detection of human papillomavirus DNA before and after development of invasive vulvar cancer.

Biopsy and surgical specimens were studied from two patients with squamous cell carcinoma in situ of the vulva and one with verrucous carcinoma of the vulva. All three patients subsequently developed invasive squamous cell carcinoma of the vulva. In two, human papillomaviruses (HPVs) 16 and 18 were found in the lesions before the development of invasive carcinoma. In the specimens with invasive squamous cell carcinoma, HPV 16 or 18 or both was found. The third patient had HPV 18 DNA in the specimen demonstrating squamous cell carcinoma in situ; when invasive squamous cell carcinoma was diagnosed 9 years later, HPVs 16 and 18 were found in the latter lesion. These findings lend support to the role of HPVs 16 and 18 in the development of invasive squamous cell carcinoma of the vulva.

Follicle stimulating hormone binding inhibiting activity and inhibin properties of human ovarian cystic and porcine follicular fluid.

Ovarian cystic fluid was obtained from 13 regularly cycling women with the operative diagnosis of ovarian serous (n = 6), mucinous cystadenomas (n = 3) and simple follicular cysts (n = 4). The effects of the fluids, after steroid extraction with charcoal treatment, on the binding of follicle stimulating hormone (FSH) to rat testicular homogenates and on the in vitro secretion of FSH and luteinizing hormone (LH) by rat pituitary cell preparations were studied. Similar studies were conducted simultaneously with steroid-free porcine follicular fluid (pFF). Human ovarian cystic fluids produced a marked inhibition of FSH-binding activity in the absence of an effect on FSH or LH secretion. In contrast, pFF exhibited both FSH-binding inhibitory (FSH-BI) and inhibin activities. Furthermore, heating did not alter the FSH-BI activity nor the inhibin properties of steroid-free human ovarian cystic fluids nor porcine follicular fluid.

The role of sex steroid receptors in obstetrics and gynecology.

PIP: Estrogen receptors (ER) and progesterone receptors (PR) play an important role in the growth and development of the reproductive tract. Estrogen and progesterone influence tissues sensitivity by regulating levels of their own receptors and receptors for other hormones, with estrogen increasing levels of ER and PR and progesterone decreasing levels of ER and PR. Serum levels of estrogen and progesterone and their effect on receptor levels within the endometrium, fallopian tube, and ovary correlate with proliferative and secretory changes observed in uterine tissue throughout the menstrual cycle. Estrogens cause rapid growth of endometrium, while estrogen and progesterone in combination moderate endometrial growth and promote glandular differentiation and secretion. Serum levels also affect receptor levels in the uterus, with estrogen enhancing uterine growth by increasing tissue levels of ER and PR and progesterone antagonizing estrogen action by decreasing receptor levels. In the postmenopausal uterus, ER content and synthesis are continually stimulated by estrogen and unopposed by progesterone. The ability of the uterus to respond to estrogen is related to the quantity of cytoplasmic ER per cell. Although the ontogenic relationship between ER, PR, cellular growth, and differentiation remains unclear, alpha-fetoprotein may play a protective role in the fetus and neonate and may be related to the onset of puberty. The role of receptors during pregnancy also needs further study, but it has been suggested that increased PR in the amnion near term removes progesterone from its protective role in the myometrium, thereby triggering labor. Insufficient production of androgen receptors in certain genotypic males results in the development of phenotypic females and may be the basis for the testicular feminization syndrome. The application of receptor technology has not yet been established in gynecologic oncology; however, in breast cancer, the success of hormonal treatments is related to the presence of ER in tumor tissue and antiestrogens are assumed to suppress tumor growth through an effect on ER. A patient's endocrine status is thought to determine the antagonist's biologic activity.^ieng

Developmental changes in the hormonal regulation of rat testis Sertoli cell adenylyl cyclase.

The stimulatory effects of FSH on Sertoli cell functions such as cAMP accumulation, protein kinase activation, and RNA and protein synthesis wane during testis maturation. However, FSH receptors increase with age and addition of cAMP stimulates these biochemical events in Sertoli cells from animals of any age. In order to determine if this loss of responsiveness to FSH was due to an inability to stimulate adenylyl cyclase, the hormonal responsiveness of this enzyme was investigated as a function of testicular development. In agreement with intact cell studies, adenylyl cyclase activity was found to be stimulated by FSH 2- to 3-fold in homogenates of testes from immature (5-20 days of age) Sertoli cell-enriched rats, while no stimulation of the enzyme by FSH was observed in similar homogenates from Sertoli cell-enriched animals 20 days of age or older. The possibility of a decrease in enzyme sensitivity to the gonadotropin as a function of maturation ws ruled out by dose-response studies. Catalytic activity of the enzyme was retained with increasing animal age as evidenced by the ability of fluoride (10 mM) to stimulate basal activity 4-fold. Hormonal responsiveness of the Sertoli cell adenylyl cyclase of mature animals could be restored, however, either by addition of the nonmetabolizable guanosine 5'-triphosphate analog, 5'-guanylyl-imidodiphosphate to homogenates or by preparation of membrane particles. We found that 5'-guanylyl-imidodiphosphate selectively potentiated FSH effects on cyclase in testicular homogenates from mature animals while having no effect on the relative degree of hormone stimulation in homogenates from immature animals, and that in contrast to homogenates, testicular membrane preparations retain their FSH responsiveness upon animal maturation.

Testicular function in strains of mice selected for differences in gonadotrophin-induced ovulation.

Mice were selected on the basis of ovulatory responses to injections of pregnant mare serum gonadotrophin (PMSG) and human chorionic gonadotrophin (hCG). Various parameters of pituitary and gonadal function as well as responsiveness to exogenous gonadotrophins were examined in males from high induced-ovulation rate (HIOV) and low induced-ovulation rate (LIOV) lines. Testicular weight, seminal vesicle weight and plasma LH levels were lower in HIOV than in LIOV males, while plasma concentrations of FSH and testosterone did not differ. Binding of FSH, but not of LH, in the testes was significantly higher in HIOV mice. Twenty-four hours after administration of hCG, plasma testosterone levels were higher and testicular LH binding sites appeared more depleted in HIOV than in LIOV males. Production of testosterone by decapsulated testes in vitro was significantly higher in HIOV than in LIOV mice under basal conditions, as well as in the presence of LH, FSH, hCG or PMSG. It was concluded that selection for differences in gonadotrophin-induced ovulation rate produced correlated differences in the steroidogenic response of the testes to gonadotrophins and that these differences may be due to divergence in the number of gonadal FSH binding sites.