Effect of Short-Term Cigarette Smoke Exposure on Body Weight, Appetite and Brain Neuropeptide Y in Mice

Abstract

Although nicotinic receptors have been demonstrated in hypothalamic appetite-regulating areas and nicotine administration alters food intake and body weight in both animals and humans, the mechanisms underlying the effects of smoking on appetite circuits remain unclear. Conflicting effects of nicotine on the major orexigenic peptide, neuropeptide Y (NPY), have been observed in the brain, but the effects of smoking are unknown. Thus, we aimed to investigate how cigarette smoking affects body weight, food intake, plasma leptin concentration, hypothalamic NPY peptide, adipose mass and mRNA expression of uncoupling proteins (UCP), and tumor necrosis factor (TNF) a. Balb/C mice (8 weeks) were exposed to cigarette smoke (three cigarettes, three times a day for 4 consecutive days) or sham exposed. Body weight and food intake were recorded. Plasma leptin and brain NPY were measured by radioimmunoassay. UCPs and TNF a mRNA were measured by real-time PCR. Food intake dropped significantly from the first day of smoking, and weight loss became evident within 2 days. Brown fat and retroperitoneal white fat masses were significantly reduced, and plasma leptin concentration was decreased by 34%, in line with the decreased fat mass. NPY concentrations in hypothalamic subregions were similar between two groups. UCP1 mRNA was decreased in white fat and UCP3 mRNA increased in brown fat in smoking group. Short-term cigarette smoke exposure led to reduced body weight, food intake, and fat mass. The reduction in plasma leptin concentration may have been too modest to increase NPY production; alternatively, change in NPY or its function might have been offset by nicotine or other elements in cigarette smoke.

Effects of tobacco smoke exposure during lactation on nutritional and hormonal profiles in mothers and offspring

“…This oxidative stress may cause a local inflammatory response, with higher IL12, tumour necrosis factor-a, neutrophils, macrophages and lymphocytes that may be related to the morphological changes observed (Zheng et al 2009, Braber et al 2010. Taken together, the morphological changes of maternal lung and high cotinine levels in serum and milk confirm the effectiveness of smoke (Arai et al 2001, Chen et al 2005, we observed that S dams did not present changes of these parameters throughout the lactation period. A simplistic explanation for this fact could be the relatively short period of smoke exposure (18 days of lactation).…”

Leptin Modulates Innate and Adaptive Immune Cell Recruitment after Cigarette Smoke Exposure in Mice

“…This is partly in line with our current and previous data, showing that 24 wk-but not 4 wk-CS exposure induces significant weight loss (51). The difference between our findings and the studies by Chen et al (47)(48)(49)(50) are most likely due to interstrain differences. These investigators used BALB/C mice, whereas in the current study C57BL/6 and C57BKS mice were used.…”

“…Recent studies from Chen et al (47)(48)(49)(50) investigated the relationship among smoking, neuropeptide Y, and weight loss and demonstrated that short-term (4 d) (47) and long-term (5, 7, and 12 wk) (48-50) CS exposure led to a significant reduction in body weight and systemic leptin concentration. This is partly in line with our current and previous data, showing that 24 wk-but not 4 wk-CS exposure induces significant weight loss (51).…”

Renal Function in Male Sprague-Dawley Rats Concurrently Exposed to Long-Term Nicotine (3-{1-Methyl-2-Pyrrolidinyl}Pyridine) and Methylated Spirits (Methyl Alcohol)

“…Previous investigations have demonstrated that short-term cigarette smoke exposure leads to a reduction in body weight and food intake, suggesting a mechanism of alteration in activity of hypothalamic neuropeptide Y by nicotine. [21,22] Others suggest that smoking-related health risks may increase during periods of significant weight loss. [23] In unanesthetised animals, weekly Na + excretion decreased in nicotine-infused animals but increased progressively in animals administered methylated spirits alone and in combination with nicotine (see Table 1).…”