摘要:

AbstractThis study was designed to correlate changes in the ratelimiting enzymes of glycogen synthesis (glycogen synthase) and glycogen breakdown (glycogen phosphorylase) with the ultrastructural changes which occur in the soleus muscle following tenotomy. Soleus muscles were removed at 1, 2, 3, 7, 14, 21, and 63 days after tenotomy and were prepared for electron microscopy or frozen for enzyme analysis. In the first 7 days posttenotomy, soleus muscle fibers underwent a series of degenerative changes, while both synthase and phosphorylase activities decreased. Over the next 8 weeks the histological appearance of the soleus muscle eventually returned to normal while synthase and phosphorylase activities increased. We suggest that recovery from tenotomy involves an increase in the energy demands of the muscle, resulting in the increased activity of the key rate‐limiting enzymes of muscle glycogen metabolism from the drastically reduced levels observed in the period before recovery begin

ISSN:0003-276X    

DOI:10.1002/ar.1092060302

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractThe urinogenital blood vessels ofAnolis equestrisandA. carolinensiswere studied using dissection, injection of silicone rubber, and histology. A new blood‐vascular connection between small veins in the pampiniform plexus at the base of the ovary and an ostial extension of the secondary oviductal vein is described. Chemical messengers could thus be carried in the blood from the ovarian venous drainage to the oviduct. Furthermore, close apposition of the secondary oviductal vein and artery provides an anatomical basis for countercurrent exchange of these messengers. A circular venous arcade, involving the supracardinal vein and branches of the oviductal veins, also is described; this arcade could serve to deliver adrenal hormones to each oviduc

ISSN:0003-276X    

DOI:10.1002/ar.1092060303

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractThe zonulae occludentes between oviductal epithelial cells were quantitatively analyzed at diestrous and estrous stages in the mouse, using the freeze‐fracture technique. Zonulae occuldentes were predominantly anastomosing at the diestrous stage, while they were predominantly parallel at the estrous stage. The lowest mean value of junctional strands comprising the zonulae occludentes was 5.3 ± 1.6. Parallel‐type zonulae occludentes had more strands than the anastomosing type. Secretory cells usually had more strands than ciliated cells. The shallowest mean depth occupied by junctional domain was 0.51 ± 0.20 μm. The depth was usually somewhat greater in anastomosing‐type zonulae occludentes than in the parallel type. It was also slightly greater in ciliated cells than in secretory cells. The depth was likely to be greater at diestrous stage than at the estrous stage. However, neither the number of strands nor the depth was significantly different between diestrous and estrous stages in homologous types of zonulae occludentes. On the basis of these results, the zonulae occludentes in oviductal epithelium are considered to be morphologically of a tight type at any time period throughout the estrous cycle. The results of lanthanum tracer experiments suggest that the zonulae occludentes in the oviductal epithelium do not always function as a barrier to the exogenous tracer.These morphological phenomena are discussed in relation to mouse fertilization

ISSN:0003-276X    

DOI:10.1002/ar.1092060304

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractThe secretory pathway and kinetics of the secretory process were studied in Brunner's glands of mice after stimulation of secretion with a parasympatho‐mimetic drug. Adult male mice were injected with pilocarpine, while unstimulated controls received saline. The animals were subsequently administered an intravenous injection of3H‐threonine, and tissue was prepared for electron microscope autoradiography at intervals ranging from 5 minutes to 2 hours after injection of the radioactive precursor. Stimulation with pilocarpine resulted in discharge of secretory granules, which was reflected in a significantly lower percentage of the cell volume occupied by granules. In both control and stimulated mice, at 5 minutes after injection of3H‐threonine, the highest percentage of silver grains over the rough endoplasmic reticulum declined at later intervals, and a peak of labeling was observed over the Golgi apparatus at 1 hour. Labeling of the secretory granules increased in the 1‐ and 2‐hour samples from both control and stimulated mice, although the relative concentration of radioactivity in both Golgi‐associated and apical secretory granules was greater in stimulated than control glands at 1 hour. The results suggest that the secretory protein produced by Brunner's glands was synthesized by the rough endoplasmic reticulum and transported to the Golgi apparatus where secretory granules were formed in both stimulated and control glands. Depletion of secretory granules by prior stimulation resulted in no change in the kinetics of arrival of radioactivity in the cell organelles involved in the secretory process. However, the drainage of the radioactive label from the rough endoplasmic reticulum was significantly slower in the stimulated glands than in the controls. The existence of two subcompartments within the rough endoplasmic reticulum is among the possible explanations for the latter

ISSN:0003-276X    

DOI:10.1002/ar.1092060305

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

ISSN:0003-276X    

DOI:10.1002/ar.1092060306

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractHistorically, postmetamorphic adult land‐phase salamanders have been shown to exhibit minimal to nonexistent limb regeneration. Hence, it has been generally accepted that these forms have lost the intrinsic capacity to regenerate a limb. Due to the experimental protocols used, an alternate explanation is also possible: that this intrinsic capacity cannot be expressed when the salamanders are maintained under adverse laboratory environmental conditions. Therefore, this study addresses two questions: (1) What are the optimal environmental conditions for long‐term survival of adult land‐phase salamanders; and (2) will complete limb regeneration occur in these salamanders if they are maintained under survival conditions. A mixed population of adultAmbystomawere tested under varying conditions of habitat, temperature, humidity, photoperiod, and food source. Complete limb regeneration was possible in 100% of four species of adult postmetamorphic land‐phaseAmbystomasalamanders given the proper environmental laboratory conditiions of a peat moss and potting soil habitat with a controlled temprature of 25°C ± 5°C, 70% or greater humidity, a 12/12 light/dark photoperiod, a diet including nightcrawlers released into their respective terraria, and an extended observation time of up to 370 days postamputation (dpa). Regeneration was completed during the following range periods for the adult salamanders:A. annulatum, 324 to 370 dpa;A. maculatum, 255 to 300 dpa;A. texanum, 215 to 250 dpa; andA. tigranum, 155

ISSN:0003-276X    

DOI:10.1002/ar.1092060307

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractDue to the great disparity between regeneration times for the larval salamander (40 days), axolotl (30+ days), newt (44 days), and adult salamander (155 to 370 days), a staging system was devised so correlative comparisons could be made between regenerative model systems. The sequence was based on two criteria: (1) the stages should be similar to previously reported sequences for the newt, axolotl, and larval salamander, and (2) the stages must be readily recognizable by examination of the external morphology in the living state. Postmetamorphic adult land‐phaseAmbystomawere amputated through the forearm, placed within survival conditions, and observed until regeneration was completed. Of the initial 160 salamanders, 157 (98%) progressed through 11 clearly defined stages of regeneration. A side‐by‐side comparison of the staging sequence for land and aquatic phase urodeles is given along with a summary of key external morphological characteristics for the adult salamander. It was noted that as the length of time for regeneration decreased, the relative ratio of the nerves innervating the limb (spinal nerves 4, 5, and 6) increased for the four species ofAmbystomaexamined:A. annulatum, 324 to 370 days postamputation (dpa) with a 1:1:1 neural tissue ratio;A. maculatum, 255 to 300 dpa with a 2:2:1 ratio;A. texanum, 215 to 250 dpa with a 2:2:2 ratio; andA. tigranum, 155 to 180 dpa with a 2:3:3

ISSN:0003-276X    

DOI:10.1002/ar.1092060308

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractTrisomy 1 embryos in mice are smaller in all dimensions, showing a developmental retardation as compared with euploid mice. Very rarely the trisomic embryos develop a typical hypotelorism with holoprosencephalon and missing olfactory nerves. Corneal distances, angles between the optic nerves and further microscopic examination showed no intermediate forms between the trisomy 1 embryos and the rare trisomy 1 embryo with hypotelorism. There seems to be a threshold, beyond which the major developmental derangement occurred. This is an experimental model showing parallels to the occasional varying phenotypes in human trisomies.

ISSN:0003-276X    

DOI:10.1002/ar.1092060309

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractThe mouse mutantDystonia musculorumexhibits pathological changes in the magnocellular neurons of the red nucleus. The present study shows that allelic differences occur in the age of onset and severity of this pathology. The magnocellular neurons of the Jackson allele (dtJ) almost completely disappear prior to 4 weeks of age while some of these cells are retained in the adult of the Albany strain (dtAlb). However, acetylcholinesterase histochemistry suggests that the remaining rubral neurons indtAlbare nonfunctional. This pathology may contribute to the severe locomotor disturbances seen in these animals.

ISSN:0003-276X    

DOI:10.1002/ar.1092060310

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractIn scanning electron microscopic (SEM) examination of 30 shark brains, a distinctive midline ridge formation on the ventricular surface of the optic tectum was found in all juveniles and adults of the three carcharhinid species (sandbar, dusky, and smooth hound) and the one lamnid species (mako) investigated. This formation is part of the mesencephalic trigeminal (Mes V) complex of these animals, and one of its remarkable features is a population of very large cerebrospinal fluid (CSF)‐contacting and supraependymal Mes V neuronal somas. These cells, whose presence in the CSF compartment is heralded by distinct premonitory ependymal bulges, are not seen in contact with CSF until the sharks are well into their first postnatal year or later. Once established, the population of CSF‐contacting and supraependymal Mes V neurons remains in substantial numbers over the life span of the animals into the period of sexual maturity. Age‐related changes in patterns of ependymal ciliation of the midline ridge formation, tending toward a state of oligociliation, are also apparent in all species examined.Similarities between the midline ridge formation of the Mes V complex and known circumventricular organs (CVOs) are discussed and it is suggested that the formation be considered as a previously unrecognized CVO. It is hypothesized that the midline ridge formation with its contingent of CSF ‐immersed neurons, by monitoring one or more CSF factors, might serve to alter the excitability of the Mes V complex as a whole and, thus, regulate intensity of biting reflexes in

ISSN:0003-276X    

DOI:10.1002/ar.1092060311

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY