Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0277787 (stigma)
 13,352 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The present study determined the amount and types of glycosaminoglycans and collagen concentrations in follicles of the domestic hen. The stigma (S; the area of follicular rupture) and nonstigma (NS) regions of the theca layer were isolated from the preovulatory follicle (F1) and an immature follicle (F2) that were to ovulate 30 min and 26 h later, respectively. Glycosaminoglycan density, which was estimated by measuring follicular uronic acid concentration (micrograms/mg dry wt), was lower (p less than 0.01) in F1S (2.6 +/- 0.1) compared to F1NS (3.4 +/- 0.2), F2S (3.4 +/- 0.1), and F2NS (3.4 +/- 0.1). Theca glycosaminoglycans consisted of approximately 58% dermatan sulfate, 20% heparan sulfate, and 22% hyaluronic acid. The F1S contained lower (p less than 0.05) amounts of dermatan sulfate and hyaluronic acid compared to F1NS, F2S, and F2NS. There was no significant difference in amounts of heparan sulfate in the F1S, F1NS, F2S, and F2NS. Collagen density, which was estimated by measuring follicular hydroxyproline concentrations (micrograms/mg dry wt), were lower (p less than 0.01) in F1S (20.3 +/- 1.4) and F2S (19.8 +/- 1.4) compared to F1NS (28.9 +/- 1.9) and F2NS (29.9 +/- 2.7). However, there was not a further decrease in collagen concentration in the F1S compared to F2S. We suggest that glycosaminoglycans may be degraded specifically in the stigma region of the preovulatory follicle prior to ovulation. The lower amount of collagen in the stigma region may decrease the tensile strength in the stigma compared to the nonstigma region regardless of maturational stage.
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PMID:Preovulatory changes in glycosaminoglycans and collagen content in the stigma region of the follicle of the domestic hen. 178 95

Collagen and acid glycosaminoglycans (GAG) in bovine tunica albuginea covering the developing follicules (FC) and corpus luteum (CL) were investigated histochemically and biochemically in order to analyze the connective tissue metabolism of the follicular wall as well as to clarify the mechanism involved in stigma repairs after ovulation at the extracellular matrix level. Histochemically, collagen fibers were observed to be loose and sparse by Azan Mallory staining and GAG were markedly stained by alucian blue in large FC. Biochemically, hydroxyproline content showed a significant decrease (43%) in large FC compared with control tunica albuginea. Uronic acid and hexosamine content tended to increase in large FC, compared with small FC. The major GAG component in FC was sulfate GAG, consisting mainly of dermatan sulfate (DS). The DS component ratio and concentration were decreased significantly in large FC, compared with small FC. Remodelling of collagen fibers and an increase in GAG content were observed in CL. The increase in GAG content was caused by a threefold increase in the component ratio and concentration of hyaluronic acid in CL, compared with other tunica albuginea. These results suggest that changes in GAG components in FC and CL are strongly related to collagen metabolism in tunica albuginea during the ovulatory cycle.
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PMID:[Collagen and acid glycosaminoglycans in bovine tunica albuginea during ovulatory cycle]. 227 5

Collagen breakdown and apoptotic cell death within the apex of the preovulatory ovine follicle are characteristic of impending rupture. It has been hypothesized that plasmin regulates these two responses by activating collagenases and tumour necrosis factor alpha (TNF-alpha), respectively. Apical plasmin bioactivity, collagenolysis, TNF-alpha-mediated fragmentation of cellular DNA (a marker of apoptosis), stigma formation, and follicular rupture in sheep were inhibited by intrafollicular injection of alpha 2-antiplasmin. Explants of follicular wall released hydroxyproline-containing peptides (degraded collagen) and bioactive TNF-alpha upon exposure to plasmin. These results indicate that plasmin has an essential intermediary role in the biomechanics of ovulatory ovarian tissue dissolution.
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PMID:Regulation of collagenolysis and cell death by plasmin within the formative stigma of preovulatory ovine follicles. 986 Nov 74

Collagen breakdown and apoptotic cell death within the apex of the preovulatory ovine follicle are hallmarks of impending ovarian rupture. An integrative mechanism is proposed whereby gonadotrophic stimulation of urokinase-type plasminogen activator secretion by the follicular-contiguous ovarian surface epithelium elicits a localized increase in tissue plasmin, which activates collagenolysis and tumour necrosis factor alpha-induced cell death within the formative ovulatory stigma.
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PMID:Plasmin-tumour necrosis factor interaction in the ovulatory process. 1069 67

The ovulatory process is extraordinary in that it constitutes a hormone-induced injury. Gonadotropin delivered via the follicular vascular wreath stimulates secretion of plasminogen activator by contiguous ovarian surface epithelial cells. A consequent elevation in interstitial plasmin activates collagenases and cleaves tumor necrosis factor alpha from its anchors on endothelium. Collagen fibril degradation and cellular death at the apex of the preovulatory follicle are hallmarks of impending ovulation. Follicular contractions rupture the weakened fabric at the apex, and the ovum, which has been disconnected from the underlying granulosa, is expelled; these components of the cascade are prostaglandin-mediated. Ovulation is required for fertility; unfortunately, it imparts a cancer risk to the ovarian surface epithelium. DNA-damaging reactive oxygen species are generated by inflammatory cells attracted into the vicinity of the ovulatory stigma. An ischemia-reperfusion flux coincident with ovulation and wound repair also contributes to genotoxicity. Potentially mutagenic lesions in DNA are normally reconciled by TP53 tumor suppressor-dependent cell-cycle arrest and base excision repair mechanisms; it is a unifocal escape that could be problematic. Epithelial ovarian cancer is a deadly insidious disease because it typically remains asymptomatic until it has metastasized to vital abdominal organs.
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PMID:Mechanisms and pathobiology of ovulation. 2175 73