Low-dose synthetic ACTH therapy is as effective for the treatment of WS as the higher doses used in previous studies. The dosage of synthetic ACTH used in the treatment of WS can be decreased as much as possible to avoid serious adverse effects.

Wistar Hannover rats, which have recently been introduced into Japan, are expected to be used in reproductive and developmental toxicity studies, yet the accumulation of background data is insufficient. This paper describes our historical data on the reproductive ability of this strain of rat. Three lots of sexually matured females (40 each) were received from CLEA JAPAN, Inc. with males of the same strain (30 or 36 each) and mated. A total of 47 dams were killed on gestation day 20 to examine their fetuses. The remaining 71 pregnant females were allowed to deliver spontaneously and observed for common reproductive parameters. The mating and fertility indices of females were both 99.2%. Overall mean numbers of implants and live fetuses at cesarean sectioning were 12.5 and 11.5, respectively. Fetal resorptions and deaths occurred at an incidence of 8.6%. Morphological examinations of fetuses revealed low incidences of spontaneous malformations (each one case of double aortic arch and absent cervical vertebral arch) and a variety of common variations. The followings are overall means of major reproductive parameters obtained from females with live birth: no. of implants, 12.5; no. of pups delivered, 11.8; viability index of pups at birth, 99.8%; and days of age at sexual maturation (vaginal opening and preputial separation), 30.3 and 42.8, respectively. Our present observations confirmed a minimal deviation among 3 lots of animals in terms of reproductive abilities. These results suggest that this strain of rat can be used in reproductive and developmental toxicity studies, although the sensitivity to toxicants remains to be elucidated.

Immunocytochemical studies were performed to describe the characteristics of cell types and their distribution in the pars distalis of Japanese long-fingered bat, Miniopterus schreibersii fuliginosus, collected at various stages of the reproductive cycle. Six distinct cell types have been identified in the pars distalis by the unlabeled immunoperoxidase technique and by the ABC method. Growth hormone (GH) and prolactin (PRL) cells were immunostained with antisera against chicken GH and ovine PRL. The GH-immunoreactive cells were round or oval orangeophilic cells distributed throughout the pars distalis with prominent aggregation in the posterolateral region. The PRL cells were pleomorphic carminophilic cells that occurred in small groups within the central and dorsocaudal regions of the pars distalis. They were sparsely distributed in the central region of the pars distalis in the hibernating bats, but increased significantly in the pregnant and lactating bats. The adrenocorticotropic (ACTH) cells were large round or polygonal amphophilic cells in the rostroventral and ventrolateral regions of the pars distalis. The thyrotropic (TSH) cells were small rounded or polygonal and distributed mainly in the ventrolateral region of the pars distalis. Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) cells were identified immunocytochemically with antisera against the specific beta subunits of ovine LH and rat FSH. There were two populations of LH and FSH cells, one aggregated in the zona tuberalis and the other scattered singly throughout the rest of the pars distalis. The aggregated cells were immunoreactive with both antisera directed to LH and FSH, while scattered cells were reactive solely with antiserum to either LH beta or FSH and exhibited seasonal variations.(ABSTRACT TRUNCATED AT 250 WORDS)

-A two-generation reproductive toxicity study was conducted with 2,4-dichlorophenol (2,4-DCP), an agent suspected of exerting endocrine disrupting effects. Wistar-Hannover rats, 24/sex/ group, were given diet containing 2,4-DCP at dose levels of 0, 500, 2000 or 8000 ppm to examine the potential effects of the test substance on parental animals and their offspring over 2 successive generations. Neither clear systemic nor reproductive toxicity of 2,4-DCP was apparent in the 500 ppm group. In the 2000 ppm group, mean body weight gain and food consumption of females were lowered significantly during the treatment period. Effects on body weights and food consumption were more serious in the 8000 ppm group, both males and females being significantly affected. Reproductive effects of the test substance were also observed in the 2000 and 8000 ppm groups dose-dependently. Observations included significantly increased uterine weights of F1 and/or F2 female weanlings and reduced numbers of implantation sites and live births of F1 parental females. These results suggest that 2,4-DCP has weak reproductive toxicity, possibly based on endocrine activity. However, the basic mechanisms for apparent estrogenic effects of 2,4-DCP remain to be elucidated.

No abstract