Leptin

Animals were treated with saline or leptin (0.3 mg/kg/day, ProSpec, Rehovot, Israel) via subcutaneous osmotic mini-pumps (ALZET, Cupertino, Calif; model 1007D, 0.5 μL/h) for 7 days as previously described [15 (link),21 (link),44 (link)].

Mice subjected to regular diet were placed in the empty recording chamber and recorded for 1 h at basal state. After they were i.p. injected with vehicle (0.9% saline; 10 ml/kg), 2-D-Glucose (Sigma; 2 g/kg b.w.), and leptin (ProSpec Inc.; 1 mg/kg b.w.) and recorded for 2 h without any interruptions. Each animal underwent all sessions with injection of saline, glucose and leptin, separated by 1 day. In the pharmacology test, the response was defined as two times standard deviation of baseline response, average AP frequency of 1 h pre-injection is the baseline response, and the average AP frequency of 1 h post-injection was used to calculate the response of glutamate or leptin.

Mice were treated with saline or Tat (3.2 µg/kg per day for 4 weeks) by intraperitoneal (i.p.) injection. The concentrations of Tat was chosen based on the study by Xiao et al. who reported that estimated Tat serum levels in PLWH is between 2 and 40 ng/mL [18 (link)]. After 3 weeks of Tat treatment, mice were separated into 2 groups and treated with either leptin (0.3 mg/kg per day, 0.417 μg/h, ProSpec, Ness-Ziona, Israel) or vehicle via subcutaneous osmotic mini-pumps (ALZET, Cupertino, CA, USA; model 1007D, 0.5 μL/h) for 7 more days, as previously described by [59 (link)]. A short-term Tat treatment (3.2 µg/kg per day for 3 days, NIH HIV Reagent Program) was also used to examine the potential direct effects of Tat on endothelial function.