摘要:

AbstractThe characteristic hypertrophying of the male reindeer neck muscles during the rutting period, which coincides with the rise in serum testosterone levels, is found to be accompanied by a significant decrease in lysosomal proteolytic activity of the neck muscle cells.Conversely, during the period of neck muscle involution following the rapid decline in serum testosterone after the rut, a marked increase in neck muscle proteolytic activity is found. These changes in lysosomal activity do not parallel the changes in feed consumption and nutritional stage of the animals during the rutting period. The lysosomal proteolytic activity of the male reindeer neck muscles thus may be, at least partly, under the control of sex steroid hormones.

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1977.tb00238.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

AbstractSkin samples were taken from forest reindeer (Rangifer tarandus L.) in order to study the distribution of apocrine tubular glands. Glands with well‐developed secretory epithelium were restricted to certain areas of the body, namely the foreleg pit, a narrow strip on the belly, the groin and on the legs. Well‐developed glands were also found in the oral angle and in the rump patch. The greatest amount was found in the ventral interdigital skin of both fore and hindfeet. In other parts of the body could only the excretory duct and a thin walled extension but no developed secretory epithelium be s

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1977.tb00239.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

AbstractThe corpora cardiaca ofSchistocercaconsist of a neurohaemal part containing mainly extrinsic neurosecretory axons coming from the brain, and of a glandular part consisting mainly of intrinsic neurosecretory cells. Some extrinsic axons penetrate into the glandular region, and innervate intrinsic corpus cardiacum neurosecretory cells. The fine structure of the latter has been examined and related to other neurosecretory cell types. Secretion occurs by exocytosis. Omega‐profiles are more frequently observed in corpora cardiaca stimulated electrically or by acetylcholine than in the control

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1977.tb00240.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

AbstractObservations have shown that amphibian larvae, contrary to what has been stated in the literature, have different kinds of eye movements. All of the anurans observed (Xenopus, Rana, Bufo, HyperoleusandBombina) have some kind of reflex eye movements effected through stimuli from the labyrinth organs as a response to movements of the body, while onlyRanaandBufohave spontaneous scanning movements. Of the urodelians (AmbystomaandTriturus), larvae ofAmbystomahave no observable eye movements, whileTrituruslarvae have reflex eye movements associated with movements of the neck, as well as spontaneous scanning movements; both kinds of movements differ from those seen in Anura.

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1977.tb00241.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

AbstractThe gastrointestinal anatomy of the frugivorous bat,Eidolon helvumwas compared with that of the insectivorous bat,Tadarida nigeriae.Both show modifications related to differences in their food habits as well as other anatomical peculiarities. The gastroesophageal junction inEidolon helvumpossesses a sphincter‐like protrusion. The posterior 10 mm of the esophagus in the same bat has well developed gastric glands, while the stomach is unexpectedly very rich in zymogenic and parietal cells. The intestine in this species is about 170 cm long; the posterior 30 cm of this is of colonic histology, though showing no external morphological difference from the small intestine. The anterior duodenum ofTadarida nigeriaehas an external protuberance consisting of mucus secreting glands. The intestine of this bat has no colon, but a very short rectum of goblet cells is presen

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1977.tb00242.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

AbstractIn the ovaries of wild yearling rabbits the histologic changes occurring between September and March were determined and related to age and season. It was found that a considerable part of the ovarian development is characterized by the growth of follicles which soon become atretic and form interstitial gland tissue. The ovarian development up to a “sub‐ovulatory” stage may be completed in the autumn in rabbits born early in the season, and later in those born late, so that by mid‐winter they are all in this stage. No ovulation was found in rabbits in the early stages of development, and it is suggested that the presence of interstitial tissue is essential for full reproductive c

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1977.tb00243.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

AbstractAfter 20 to 50 days in sea water (SW), regressive changes of the kidney occur at the same rate in intact and hypophysectomized eels (Anguilla anguilla). In SW, ovine prolactin (oPRL) increases plasma electrolytes and restores a fresh water (FW) kidney structure; cell height and nuclear area increase in main segments of the nephron: first (P1) and second proximal (P2), distal (D) and initial collecting (C) tubules. A differentiation of new tubules also occurs. This effect is less intense after hypophysectomy and greater in FW. A dose of 10 μg/g body weight/day for 10 days in SW produces some harmful renal effects, barely detected at 6 μg/g/day. The kidney plays a minor role in osmotic adjustment in SW when PRL secretion is reduced (intact eels) or suppressed (hypophysectomized); PRL treatment reverses effects of SW adaptation. An inhibition of gill sodium extrusion may explain the high blood sodium level; however, kidney histological changes suggest a renal participation, perhaps through reduced water permeability as inPlatichthy

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1977.tb00244.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY