Nutritional supplementation of nucleotides restores opioid CNS-mediated phenomena in mice

Previous experiments have demonstrated that suppression of immune function by either cyclosporin A or by a nucleotide free (NF) diet results in attenuation of morphine withdrawal symptoms in mice suggesting that immune status impacts CNS opioid-related phenomena. The present study elaborates on these initial findings by examining the effects of repletion of the NF diet with nucleotides or their precursors on opiate withdrawal. Female Balb/c mice were divided into six groups: a control group (C) given a standard lab chow diet and five experimental groups each given one of the following diets: a nucleotide free diet (NF); the NF supplemented with 0.25% RNA (NFR 0.25); the NF supplemented with 2.5% RNA (NFR 2.5) the NF supplemented with 0.06% uracil (NFU 0.06); the NF supplemented with 0.6% uracil (NFU 0.6). The mice were made morphine dependent by subcutaneous implantation of morphine pellets. Seventy-two hours after morphine pellet implantation, withdrawal was precipitated with naloxone (2 mg/kg). The mice were then observed and two indicators of withdrawal scored: jumping and diarrhea. The NF, NFR 0.25, NFR 2.5 and NFU 0.06 groups demonstrated significantly attenuation of the withdrawal signs relative to control animals. The NFU 0.6 group, however, had withdrawal scores restored to near control levels for both jumping and diarrhea. This suggests that nucleotides, particularly uracil, may play an important role in the immune-to-brain signaling pathway.

Quantitative analysis of collagen accumulation during protein malnutrition

It is generally believed that protein malnutrition is detrimental to proper wound healing. However, there is limited evidence in the literature to support this. The authors studied the effect of protein depletion on the accumulation of collagen to determine the quantitative changes taking place in the healing wound. Polytetrafluoroethylene (PTFE) wound cylinders were implanted subcutaneously in 30 male Sprague-Dawley rats. The rats were divided into two groups and fed either chow (C) (n = 12) or an isocaloric protein-free (PF) diet (n = 18). Seven, 14, and 21 days later, the rats were weighed, bled, and wound cylinders harvested. PTFE cylinder collagen content, hematologic parameters, total serum protein, and serum albumin were determined. The rats with the PF diet had significant (P < .001) weight loss at all time-points (day 7, PF = 176.2 +/- 3.2, F = 252.4 +/- 3.8; day 14, PF = 154.8 +/- 3.6, F = 289.3 +/- 9.2; day 21, PF = 150.8 +/- 3.9, F = 307.6 +/- 12.2). Total serum protein was also depleted as compared with controls (P < .001). White blood cell counts were significantly higher on day 7 (PF = 7.5 +/- 0.9, C = 4.4 +/- 0.9, P < .03) in the PF group; however, this was not sustained, and there was no difference between the groups on days 14 and 21. Collagen content (micrograms of 5-hydroxyproline [OHP] per centimeter PTFE) was diminished on day 7 (PF = 12.7 +/- 2.0, C = 24.7 +/- 3.4, P < .03). No difference was seen on day 14.(ABSTRACT TRUNCATED AT 250 WORDS)

Suppression of opiate withdrawal by cyclosporin A and dietary modification

It has been demonstrated in a murine model that a defined diet (Purina Basal Diet 5755) has immunosuppressive effects similar to cyclosporin A (CsA). It was also shown that CsA treatment in opiate dependent rats can attenuate the severity of opiate withdrawal. In this study, an opiate dependence model was established in Balb/c mice to assess the effects of the 5755 diet and CsA on morphine withdrawal - a CNS mediated phenomenon. Three groups of mice were used; a chow-fed control group (Purina 5008), a chow fed CsA treated group, and a group maintained on the 5755 diet. Morphine dependence was established by subcutaneous implantation of a 100 mg morphine base pellet under ether anesthesia. Seventy-two hours after pellet implantation, withdrawal was precipitated by a single injection of the opiate antagonist naloxone (2 mg/kg ip). Two indicators of withdrawal were assessed; jumping and diarrhea. The data demonstrated that both CsA and the 5755 diet resulted in significant attenuation of withdrawal symptoms with the 5755 diet being the most effective of the two. These findings suggest that immune modulation elicited by the 5755 diet and CsA treatment has a direct impact on the CNS opioid function.