Impact of age and sex on response to ischemic preconditioning in the rat heart: differential role of the PI3K–AKT pathway

2013 ◽  
Vol 91 (8) ◽  
pp. 640-647 ◽  
Author(s):  
Veronika Ledvenyiova ◽  
Dezider Pancza ◽  
Jana Matejiková ◽  
Miroslav Ferko ◽  
Iveta Bernatova ◽  
...  

Sex and aging represent important factors that determine morbidity and mortality due to cardiovascular diseases in the human population. This study aimed to investigate the impact of aging on the response to ischemia–reperfusion in male and female rat hearts, and to explore a potential role of the PI3K–Akt pathway in the cardioprotective effects of ischemic preconditioning (IPC) in the myocardium of younger and older adult males and females. Langendorff-perfused nonpreconditioned and preconditioned hearts of 12- and 18-week-old male and female Wistar rats were subjected to regional ischemia and reperfusion with or without prior perfusion with the PI3K inhibitor wortmannin for the evaluation of ischemia-induced arrhythmias and the size of myocardial infarction (infarct size; IS). Aging did not modify IS in both sexes; however, it markedly increased susceptibility to arrhythmias. Although IPC effectively reduced IS in males and females of both ages, only the hearts of males and 18-week-old females benefited from its antiarrhythmic effect. In the preconditioned 12-week-old females, but not the 18-week-old females, and in males of both ages, wortmannin blunted the anti-infarct effect of IPC. In conclusion, activation of the PI3K–Akt pathway plays an important role in protection against lethal injury conferred by IPC in males irrespective of age. The IS-limiting effect of IPC appears to be PI3K–Akt-dependent only in the 12-week-old females.

2020 ◽  
Vol 22 (8) ◽  
pp. 1364-1373 ◽  
Author(s):  
Angeline J Dukes ◽  
James P Fowler ◽  
Valeria Lallai ◽  
Anna N Pushkin ◽  
Christie D Fowler

Abstract Introduction During adolescence, exposure to nicotine or cannabis independently induces effects on neuromaturation and later cognitive function. However, the potential effect of both drugs under co-use conditions has become of increasing concern given the prevalence of e-cigarettes, legalization of cannabis, and availability of synthetic “spice” cannabinoid agonists. Aims and Methods The current studies investigated the effects of exposure to a cannabinoid receptor agonist (WIN55,212-2) and/or nicotine over a discrete time period in mid-adolescence on later intravenous nicotine self-administration in adult male and female mice. We further examined whether cannabinoid agonist administration in adulthood would alter nicotine reinforcement, with either acute or chronic pairing across 7 days. Results We found that adult males exhibited increased nicotine self-administration at a lower, rewarding nicotine dose following adolescent cannabinoid exposure, either alone or with nicotine coadministration. In contrast, adult females demonstrated an opposing effect in which adolescent cannabinoid and nicotine coexposure resulted in decreased nicotine intake compared with the nicotine only and control groups. Furthermore, after maintaining nicotine self-administration across sessions, pretreatment with a low dose of the cannabinoid agonist decreased nicotine intake in both male and female control mice, and this lowering effect was evidenced after both acute and chronic treatment. However, the cannabinoid agonist was ineffective in altering nicotine intake in mice previously exposed to nicotine, cannabinoid agonist, or both during adolescence. Conclusions These data provide evidence that adolescent drug exposure can alter later nicotine reinforcement in a sex-specific manner and can further modulate the effectiveness of interventions in reducing nicotine intake during adulthood. Implications These studies demonstrate a significant impact of nicotine, cannabinoids, or coexposure on developmental processes during adolescence. Differential effects were observed within each sex, with opposing results found for cannabinoid exposure on nicotine intake in males and females. Intriguingly, we also evidenced resistance to the lowering effects of a cannabinoid agonist on nicotine intake in adulthood based on adolescent drug exposure. Thus, these findings have important implications for our understanding of the impact of nicotine and cannabinoids (eg, Δ9-tetrahydrocannabinol (THC) and synthetic “spice” cannabinoids) during development, with further implications for the effectiveness of therapeutic interventions based on prior drug exposure in youth.


1968 ◽  
Vol 58 (4) ◽  
pp. 600-612 ◽  
Author(s):  
Robert Boyd ◽  
Donald C. Johnson

ABSTRACT The effects of various doses of testosterone propionate (TP) upon the release of luteinizing hormone (LH or ICSH) from the hypophysis of a gonadectomized male or female rat were compared. Prostate weight in hypophysectomized male parabiotic partners was used to evaluate the quantity of circulating LH. Hypophyseal LH was measured by the ovarian ascorbic acid depletion method. Males castrated when 45 days old secreted significantly more LH and had three times the amount of pituitary LH as ovariectomized females. Administration of 25 μg TP daily reduced the amount of LH in the plasma, and increased the amount in the pituitary gland, in both sexes. Treatment with 50 μg caused a further reduction in plasma LH in males, but not in females, while pituitary levels in both were equal to that of their respective controls. LH fell to the same low level in partners of males or females receiving 100 μg TP. When gonadectomized at 39 days, males and females had the same amount of plasma LH, but males had more stored hormone. Pituitary levels were unchanged from controls following treatment with 12.5, 25 or 50 μg TP daily, but plasma values dropped an equal amount in both sexes with the latter two doses. Androgenized males or females, gonadectomized when 39 days old, were very sensitive to the effects of TP and plasma LH was significantly reduced with 12.5 μg daily. Pituitary LH in androgenized males was higher than that of normal males but was reduced to normal by small amounts of TP. The amount of stored LH in androgenized females was not different from that of normal females and it was unchanged by any dose of TP tested. Results are consistent with the conclusion that the male hypothalamic-hypophyseal axis is at least as sensitive as the female axis to the negative feedback effects of TP. Androgenization increases the sensitivity to TP in both males and females.


2021 ◽  
pp. 026988112199688
Author(s):  
Eduardo R Butelman ◽  
Caroline Baynard ◽  
Bryan D McElroy ◽  
Thomas E Prisinzano ◽  
Mary Jeanne Kreek

Background: Novel short-acting κ(kappa)-opioid receptor selective antagonists are translational tools to examine the impact of the κ-receptor/dynorphin system in assays related to central nervous system dysfunction (e.g., substance use disorders, anhedonia and depression). The effects of such compounds have been compared in males and females under very limited conditions. Aims: The goal of this study was to examine potential sex differences in the effects of a κ-agonist and a short-acting κ-antagonist in an ethologically relevant test of anhedonia, the “splash test” of self-grooming, and also in the forced swim test and in locomotor activity. Methods: We examined the dose-dependence of grooming deficits caused by the κ-agonist U50,488 (0.1–3.2 mg/kg intraperitoneal (i.p.)) in gonadally intact adult male and female C57BL/6J mice. We then compared the effects of the short-acting κ-antagonist LY2795050 ((3-chloro-4-(4-(((2S)-2-pyridin-3-ylpyrrolidin-1-yl)methyl) phenoxy)benzamide)); 0.032–0.1 mg/kg i.p.) in blocking grooming deficits caused by U50,488 (3.2 mg/kg). The effects of LY2795050 were also studied in the forced swim test (FST). The effects of LY2795050 in blocking the locomotor depressant effects of U50,488 (10 mg/kg) were also studied. Results: U50,488 produced dose-dependent grooming deficits in male and female mice, and LY2795050 prevented these effects. In contrast, LY2795050 decreased immobility in the FST in males at a dose of 0.1 mg/kg, but not in females, up to a dose of 0.32 mg/kg. Also, LY2795050 (0.32 mg/kg) prevented and also reversed the locomotor-depressant effects of U50,488 (10 mg/kg), in males and females. Conclusions: This study further implicates the κ-receptor system in ethologically relevant aspects of anhedonia, and confirms sexual dimorphism in some behavioral effects of novel κ-antagonists.


2017 ◽  
Vol 32 (7) ◽  
pp. 559-567 ◽  
Author(s):  
Teresinha Regina Ribeiro de Oliveira ◽  
Geraldo Ferreira de Oliveira ◽  
Ricardo Santos Simões ◽  
Eduardo Hiroshi Tikazawa ◽  
Hugo Pequeno Monteiro ◽  
...  

2000 ◽  
Vol 278 (1) ◽  
pp. H305-H312 ◽  
Author(s):  
Ryan M. Fryer ◽  
Janis T. Eells ◽  
Anna K. Hsu ◽  
Michele M. Henry ◽  
Garrett J. Gross

We examined the role of the sarcolemmal and mitochondrial KATPchannels in a rat model of ischemic preconditioning (IPC). Infarct size was expressed as a percentage of the area at risk (IS/AAR). IPC significantly reduced infarct size (7 ± 1%) versus control (56 ± 1%). The sarcolemmal KATP channel-selective antagonist HMR-1098 administered before IPC did not significantly attenuate cardioprotection. However, pretreatment with the mitochondrial KATP channel-selective antagonist 5-hydroxydecanoic acid (5-HD) 5 min before IPC partially abolished cardioprotection (40 ± 1%). Diazoxide (10 mg/kg iv) also reduced IS/AAR (36.2 ± 4.8%), but this effect was abolished by 5-HD. As an index of mitochondrial bioenergetic function, the rate of ATP synthesis in the AAR was examined. Untreated animals synthesized ATP at 2.12 ± 0.30 μmol ⋅ min−1 ⋅ mg mitochondrial protein−1. Rats subjected to ischemia-reperfusion synthesized ATP at 0.67 ± 0.06 μmol ⋅ min−1 ⋅ mg mitochondrial protein−1. IPC significantly increased ATP synthesis to 1.86 ± 0.23 μmol ⋅ min−1 ⋅ mg mitochondrial protein−1. However, when 5-HD was administered before IPC, the preservation of ATP synthesis was attenuated (1.18 ± 0.15 μmol ⋅ min−1 ⋅ mg mitochondrial protein−1). These data are consistent with the notion that inhibition of mitochondrial KATPchannels attenuates IPC by reducing IPC-induced protection of mitochondrial function.


1983 ◽  
Vol 11 (1) ◽  
pp. 23-28 ◽  
Author(s):  
Frank J. Prerost

Considering the relaxation of sex role restraints and the convergence of male/female reactions to erotica, this study examined the impact of humorous sexual stimuli on adult males and females. Results showed the importance of personal sexual experience and enjoyment with sexual expression on the reactions to sexual humor. Sexist ideas within sexual humor was a significant factor in influencing female appreciation of sexual jokes. Yet some females, depending on life experiences, evidenced cross-sex attitudes in humor preferences.


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