Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P50583 (asymmetrical)
 12,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Spermatozoa of the shrew Suncus murinus, a mammal with abdominal testes, exhibit four unusual features: a giant acrosome; a dorsoventral asymmetry of their spermiation; a dorsoventral asymmetry of their head surface character; and also apparent surface maturity as they enter the epididymis. A Sertoli cell-periacrosomal cisternal complex envelops the giant acrosome during spermatid maturation. Spermiation is heraled by asymmetrical disorganization of the subplasmalemmal components of this complex and is completed by retraction of the Sertoli cell from the ventral and then the dorsal face of the spermatid head. This sequence or release is correlated with an asynchronous acquisition of negative surface charges on the spermatid head-demonstrable on glutaraldehyde-stabilized cells by the binding at pH 1.8 of positively charged colloidal particles of ferric oxide. Mature epididymal spermatozoa exhibit an asymmetry in the patterns of distribution of bound colloid over the dorsal vs. ventral surfaces of the sperm head, as well as regional differences between the tail midpiece and principal piece. Surface distributions of anionic residues and lectin (Con A)-binding sites characteristic of mature Suncus spermatozoa are demonstrable within the testis, unlike the situation in most nannals where distinct modifications of the sperm surface occur during epididymal passage.
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PMID:Asymmetry of spermiation and sperm surface charge patterns over the giant acrosome in the musk shrew Suncus murinus. 126 97

The transformation of hamster sperm motility during capacitation in vitro and during maturation in the caudal epididymis was analyzed and compared using videomicrography. Sperm recovered from the distal portion of the caudal epididymis, as well as ejaculated sperm recovered from the uterus exhibited low amplitude, planar flagellar beating. By 3 hr of incubation under capacitating conditions, the caudal epididymal sperm were swimming in helical patterns apparently produced by significantly increased acuteness of flagellar bending and by torsion seen as abrupt, periodic turning of the head. By 4 hr, most sperm were hyperactivated, swimming in circles resulting from asymmetrical, planar flagellar bending that was significantly more acute than the preceding patterns. When motility parameters of fresh sperm were compared with those of sperm swimming in the transitional helical pattern and with hyperactivated sperm, transitional sperm had significantly higher net and average path velocities than the others, indicating that they covered space at the greatest rate. This suggests that the transitional phase plays an important role in sperm transport. Sperm recovered from the proximal region of the caudal epididymis, near the corpus, swam in either the helical or hyperactivated patterns, or a mixture of the two. The means of their flagellar curvature ratios and linear indices were intermediate between helical and hyperactivated mean values. Thus, sperm undergoing final maturation in the caudal epididymis reverse the pattern of development of hyperactivation. Also, the development of hyperactivated motility must therefore entail induction of a preexisting potential for flagellar movement, rather than a maturational process.
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PMID:Hamster sperm motility transformation during development of hyperactivation in vitro and epididymal maturation. 319 45

Hypophysectomy decreased the basal rate of glucose metabolism in segments of epididymal fat studied in vitro and lowered their maximum capacity to use glucose. However, hypophysectomy changed neither the sensitivity to insulin nor the magnitude of the response when the results were expressed relative to the basal rate of glucose metabolism. Adipocytes isolated from both hypophysectomized and normal rats exhibited a higher basal rate of glucose metabolism than cells remaining in situ in the contralateral tissues, but this consequence of cell isolation was more pronounced for adipocytes of hypophysectomized than normal rats. Glucose metabolism could not be further increased by exposure of the adipocytes of hypophysectomized rats to insulin, whereas insulin produced a 3-to 5-fold stimulation of glucose oxidation in normal adipocytes. The effects of insulin and hypophysectomy on the transport of the nonmetabolizable sugar L-[1-14C]arabinose in tissue segments and isolated adipocytes were also studied. Uptake of L-arabinose was usually more rapid in segments of epididymal fat of normal rats than in segments of tissue obtained from hypophysectomized rats and was significantly accelerated by insulin in both groups. Uptake of L-arabinose was more rapid than normal in adipocytes isolated from hypophysectomized rats and, like glucose metabolism, could not be accelerated by insulin. The same concentration of insulin markedly promoted arabinose uptake in normal adipocytes. Efflux of L-arabinose from segments of tissue from hypophysectomized rats was twice as rapid as that from normal tissue and, in contrast with the rate of efflux from normal tissues, was not accelerated by insulin. The data suggest that in the absence of pituitary secretion, sugar transport in the adipocyte membrane may be asymmetrical. The data also support the view that hypophysectomy renders adipocytes more susceptible than normal to the cell isolation procedure which maximally accelerates glucose utilization and inward transport of arabinose in these cells.
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PMID:Effects of hypophysectomy and cell isolation on the transport of L-arabinose by adipocytes. 388 May 39

Caudal epididymal spermatozoa of golden hamsters were incubated in capacitation medium. Their movement patterns changed as they became hyperactivated and underwent the acrosome reaction. To understand the basic mechanism by which changes in movement pattern are brought about, digital image analysis was carried out on the flagellar movements recorded with a video system. The degree of flagellar bending increased with incubation time, especially in the proximal midpiece. The hyperactivated spermatozoa had remarkably asymmetrical flagellar waves of large amplitude because either the bends in the same direction as the hook of the head (referred as the "pro-hook bend") or the bends in the opposite direction to the hook of the head (referred as the "anti-hook bend") extremely increased their curvature; whereas, the acrosome-reacted spermatozoa had relatively symmetrical flagellar waves of large amplitude because both the pro- and anti-hook bends remarkably increased their curvature. Beat frequency significantly decreased while wavelength of flagellar waves increased after hyperactivation and further after the acrosome reaction. These results suggest that both extreme pro- and anti-hook bends are essential in the acrosome-reacted spermatozoa even though beat frequency decreased markedly.
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PMID:Quantitative analysis of flagellar movement in hyperactivated and acrosome-reacted golden hamster spermatozoa. 1183 83