Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.1.1 (hexokinase)
 5,274 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of streptozotocin-induced diabetes mellitus on the activity of discrete regions of the brain were studied with histochemical localization and photodensitometric quantification of the metabolic enzyme, hexokinase. Two weeks after a single injection of streptozotocin (65 mg/kg, i.p.), plasma glucose and osmolarity levels were elevated, and plasma sodium concentrations were depressed. These changes were reversed in diabetic rats treated with insulin. Accompanying these symptoms of diabetes were significant increases in hexokinase activity in the magnocellular division of the paraventricular nucleus of the hypothalamus (mPVH, 12.1%), the medial subdivision of the nucleus of the tractus solitarius (mNTS, 15.5%), and the commissural subdivision of the NTS (cNTS, 10.9%). An increase, though just below the level of significance, was also observed in the supraoptic nucleus of the hypothalamus (SON, 11.5%). The increases in hexokinase activity were completely reversed in the cNTS (and SON) and only partly reversed in the mPVH and mNTS of insulin-treated diabetic rats. No changes in hexokinase activity were seen in the subfornical organ, medial preoptic area, parvocellular division of the PVH, locus coeruleus, or dorsal motor nucleus of the vagus of diabetic rats. These results reinforce the idea that the brain is not exempt from changes associated with diabetes mellitus and suggest that metabolic alterations in the mPVH (and SON) and two divisions of the NTS are likely related to changes in vasopressin production and blood volume, respectively.
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PMID:Alterations in brain hexokinase activity associated with streptozotocin-induced diabetes mellitus in the rat. 222 10

Histochemical localization and photodensitometric quantification of the metabolic enzyme, hexokinase (HK), were used to study changes in brain metabolic activity that occur during the development of (5 days) and recovery from (7 days) dehydration. In water-deprived (WD) rats, HK activity increased after 2 days in the subfornical organ (SFO, 22%), nucleus circularis (NC, 36%), parvo- and magnocellular divisions of the paraventricular nucleus (pPVH, 17%; mPVH, 46%) and supraoptic nucleus (SON, 46%). Activity in SFO declined to control levels at 3 days but increased again thereafter. In pPVH, mPVH, and SON, activity was elevated until the end of the experiment. In NC, activity returned to control levels within 2 days of drinking by the rats. In salt-loaded (2% NaCl in water) rats, changes were similar to those of WD rats up to 2 days of dehydration (SFO, 25%; NC, 20%; pPVH, 16%; mPVH, 38%; SON, 50%). Activity in SFO and pPVH returned to control levels after 3 days and remained unchanged. In mPVH, SON, and NC, activity remained elevated and declined to control levels when salt-free water was provided. Results confirm that water deprivation is a stronger dehydrating stimulus than salt loading. In addition, metabolic activity, as measured by HK activity, varies daily during periods of dehydration and rehydration. These changes cannot always be predicted from results obtained only at the end of a period of dehydration. It is concluded that it is necessary to study dehydration-induced changes in brain metabolism on a daily basis to more fully understand the roles of discrete brain regions in the regulation of body fluids.
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PMID:Regional alterations in hexokinase activity within rat brain during dehydration and rehydration. 271 47

The effects of intracerebroventricular (ICV) colchicine (70 micrograms per rat) on systolic pressures and levels of hexokinase activity in the hypothalamic paraventricular (PVH) and supraoptic (SON) nuclei were investigated in adult normotensive and spontaneously hypertensive rats (SHR). One day after colchicine injection, systolic pressures had dropped significantly in Sprague-Dawley (SD) rats, Wistar-Kyoto (WKY) rats, and SHR; the largest decrease was seen in SHR. Postinjection pressures in SHR were within the normotensive range. No further decreases were observed two days after injections. Quantitative analysis of hexokinase activity in control animals verified that the parvo- and magnocellular PVH (but not SON) of SHR contained significantly lower levels of hexokinase than in WKY or SD rats. Two days after colchicine injection, hexokinase activities in pPVH and mPVH were similar in all three strains. Activity had decreased significantly in SD and WKY rats. In SHR, no differences between control and postinjection values were found. Hexokinase activity in SON was significantly decreased to the same extent in all strains. As metabolic activity in the pPVH, mPVH, and SON decreased after colchicine injection in normotensive rats whereas no such decreases occurred in the pPVH and mPVH of SHR, the findings suggest that colchicine may have differential effects on the metabolic activity of specific cell groups in brain depending on the physiological state of the animal.
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PMID:Effects of colchicine on hexokinase activity in the paraventricular and supraoptic nuclei of spontaneously hypertensive and normotensive rats. 280 10