Abstract. The present study characterized the different hormonal responses to stress in the endocrine milieu with different circulating levels of prolactin (PRL) and examined the direct effects of PRL on adrenal steroidogenic responses to adrenocorticotropic hormone (ACTH) using experimentally induced hyperprolactinemia and hypoprolactinemia male rat models. Hyperprolactinemia was induced by transplantation of two adult female rat anterior pituitary glands under the kidney capsule for 2 weeks, and hypoprolactinemia was induced by daily subcutaneous injection of 2-Bromo-alphaErgocryptine (CB-154) for 2 weeks. Under stress conditions, the peak levels of ACTH were significantly higher in hypoprolactinemia than normal rats. Meanwhile, the peak levels of corticosterone and progesterone were significantly higher in hyperprolactinemia than in normal and hypoprolactinemia stressed rats. Results of in vitro experiments showed that adrenocortical cells in hyperprolactinemia exhibited higher basal levels of corticosterone and progesterone rats than normal and hypoprolactinemia rats. The stimulatory effect of ACTH on corticosterone and progesterone release was higher in hyperprolactinemia than hypoprolactinemia rats. In addition, PRL increased the stimulatory effect of ACTHinduced corticosterone secretion in all rat models. These results suggest that hypoprolactinemia and hyperprolactinemia rats exhibit marked differences in the response of their hypothalamic-pituitary-adrenal (HPA) axis during acute restrain stress. Additionally, these studies emphasize that the adrenal cortex might be more sensitive to ACTH stimulation in endocrine milieu with high levels of PRL resulting in high corticosterone and progesterone release.
Based on previous conflicting reports that the two forms of pig-tailed macaque (northern and southern) exist as separate species, subspecies, or forms, and that their boundary zone lies in Thailand, a survey of the distribution range and morphology of pig-tailed macaques in Thailand was conducted during 2003-2010. We first conducted a questionnaire survey. Questionnaires were sent to 7,410 subdistricts throughout Thailand. We then traveled to 72 of the 123 subdistricts reporting the presence of pig-tailed macaques. However, due to a lack of reports of the presence of free-ranging pig-tailed macaques living south of the Isthmus of Kra, a survey of pet pig-tailed macaques was also conducted during 16-24 September 2011. Furthermore, 35 wild northern pig-tailed macaques inhabiting northern Thailand (13°13'N, 101°03'E) were temporarily caught and their morphological characters were measured and then compared to those of the southern form captured from Sumatra, Indonesia. Although largely allopatric, the ranges of the northern and southern pig-tailed macaques in Thailand were found to have a partially sympatric boundary at the Surat Thani-Krabi depression (8-9°30'N). Morphologically, these two forms were very distinctive, with different morphological characters such as the crown patch, the white color of the triangle above the eyes, the red streak at the external rim of the eyes, pelage color, ischial callosity, tail length and carriage, facial height, and limb length in both sexes, and patterns of sex skin swelling and reddening in females. These differences in morphological characters between the northern and southern forms should help settle the problems of their taxonomy.
Background/purpose Acemannan, a β-(1–4)-acetylated polymannose extracted from Aloe vera gel, has been proposed as biomaterial for bone regeneration. The aim of this study was to investigate the effect of acemannan in calvarial defect healing. Materials and methods Acemannan was processed to freeze-dried sponge form and disinfected by UV irradiation. Thirty-five female Sprague–Dawley rats were used in the in vivo study. Seven-mm diameter mid-calvarial defects were created and randomly allocated into blood clot control (C), acemannan 1 mg (A1), 2 mg (A2), 4 mg (A4), and 8 mg (A8) groups (n = 7). After four weeks, the calvarial specimens were subjected to microcomputed tomography (microCT) and histopathological analysis. Results MicroCT revealed a significant increase in bone surface and bone volume in the A1 and A2 groups, and tissue mineral density in the A4 and A8 groups compared with the control group ( p < 0.05). Histologically, the acemannan-treated groups had denser bone matrix compared with the control group. Conclusion Acemannan is an effective bioactive agent for bone regeneration, enhancing bone growth as assayed in two- and three-dimensions.
Abstract. Killer whales were used to evaluate peripartum changes and interactions between body temperature and circulating progesterone concentration. Daily body temperature was measured between 0800 h and 0830 h before activity. Body temperature clearly increased during the first phase of pregnancy, and this was followed by a gradual decline until full term. The initial increase was paralleled by circulating levels of progesterone. A decrease in body temperature was first detected on day 5 (p<0.01) before parturition, and body temperature decreased significantly every 2 days until delivery. Five days before delivery, body temperature was 0.3 C lower than the mean value during the pregnancy period, and the decrease was more marked on day 1 before delivery (0.8 C). Serum progesterone levels during pregnancy showed a general pattern of initial rapid elevation (increasing phase), followed by a gradual decline (decreasing phase) throughout the remainder of pregnancy. However, statistically significant correlations between body temperature and progesterone pattern were only found only during the increasing phase. These results suggest that monitoring body temperature variation can be considered valuable for predicting impending parturition in killer whales.
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