Caloric restriction reduces proteinuria in male rats with established nephropathy.

Reducing proteinuria is a crucial approach in preventing kidney function loss. Previous preclinical studies indicated that caloric restriction (CR) imposed at a young age protects against age-related proteinuria. However, these studies have not explored CR in established renal disease. Therefore, this study aimed to investigate the impact of CR on established proteinuria. Rats, aged 12 ± 2 weeks, were administered 2.1 mg/kg of Adriamycin. Six weeks after injection, protein excretion was measured, and a [13 N]ammonia positron emission tomography (PET) scan was conducted to assess kidney perfusion. After 7 weeks rats were divided into four groups: ad libitum (AL) and CR groups fed either a 12% or a 20% protein diet. All groups were treated for 12 weeks. Blood pressure was measured and a second PET scan was acquired at the end of the study. The animals subjected to CR exhibited a 20.3% decrease in protein excretion (p = 0.003) compared to those in the AL groups. Additionally, blood pressure in the CR group was 21.2% lower (p < 0.001) than in the AL groups. While kidney function declined over time in all groups, the 20% CR group demonstrated the smallest decline. Thus CR effectively reduces urinary protein excretion and lowers blood pressure in rats with established proteinuria.

Carbocyclic analogue of 3-deazaadenosine: a novel antiviral agent using S-adenosylhomocysteine hydrolase as a pharmacological target.

The carbocyclic analogue of 3-deazaadenosine (3-deaza-C-Ado) has been synthesized and found to have antiviral activity in cell culture against herpes simplex virus type 1, vaccinia virus, and HL-23 C-type virus. It is relatively noncytotoxic at effective antiviral concentrations and is not subject to deamination or phosphorylation. It acts as a competitive inhibitor of S-adenosyl-L-homocysteine hydrolase, is at best a poor substrate, and does not inactivate the enzyme significantly. 3-Deaza-C-Ado may cause a selective inhibition of the methylation of the polynucleotide 5' cap of viral mRNA via higher cellular concentrations of S-adenosyl-L-homocysteine, resulting from the inhibition of S-adenosylhomocysteine hydrolase in infected cells, since increases in the intracellular level of S-adenosylhomocysteine, but no effects on DNA or RNA synthesis, were observed after incubation of these cells with it.