| Autor: |
K.P. Briski, Prabhat R. Napit, Md. Haider Ali, A.A. Alshamrani, A.R. Alhamyani, Khaggeswar Bheemanapally, Mostafa M.H. Ibrahim |
| Jazyk: |
angličtina |
| Rok vydání: |
2021 |
| Předmět: |
|
| Zdroj: |
Endocrine and Metabolic Science, Vol 3, Iss , Pp 100087- (2021) |
| Druh dokumentu: |
article |
| ISSN: |
2666-3961 |
| DOI: |
10.1016/j.endmts.2021.100087 |
| Popis: |
Ventromedial hypothalamic nucleus (VMN) glycogen metabolism affects local glucoregulatory signaling. The hindbrain metabolic-sensitive catecholamine (CA) neurotransmitter norepinephrine controls VMN glycogen phosphorylase (GP)-muscle (GPmm) and -brain (GPbb) type expression in male rats. Present studies addressed the premise that CA regulation of hypoglycemic patterns of VMN glycogen metabolic enzyme protein expression is sex-dimorphic, and that this signal is responsible for sex differences in acclimation of these profiles to recurrent insulin-induced hypoglycemia (RIIH). VMN tissue was acquired by micropunch-dissection from male and female rats pretreated by caudal fourth ventricular administration of the CA neurotoxin 6-hydroxydopamine (6OHDA) before single or serial insulin injection. 6-OHDA averted acute hypoglycemic inhibition of VMN glycogen synthase (GS) and augmentation of GPmm and GPbb protein expression in males, and prevented GPmm and -bb down-regulation in females. Males recovered from antecedent hypoglycemia (AH) exhibited neurotoxin-preventable diminution of baseline GS profiles, whereas acclimated GPmm and -bb expression in females occurred irrespective of pretreatment. RIIH did not alter VMN GS, GPmm, and GPbb expression in vehicle- or 6-OHDA-pretreated animals of either sex. VMN glycogen content was correspondingly unchanged or increased in males versus females following AH; 6-OHDA augmented glycogen mass in AH-exposed animals of both sexes. RIIH did not alter VMN glycogen accumulation in vehicle-pretreated rats of either sex, but diminished glycogen in neurotoxin-pretreated animals. AH suppresses baseline GS (CA-dependent) or GPmm/GPbb (CA-independent) expression in male and female rats, respectively, which corresponds with unaltered or augmented VMN glycogen content in those sexes. AH-associated loss of sex-distinctive CA-mediated enzyme protein sensitivity to hypoglycemia (male: GS, GPmm, GPbb; female: GPmm, Gpbb) may reflect, in part, VMN target desensitization to noradrenergic input. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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