DMSO as a vehicle for central injections: tests with feeding elicited by norepinephrine injected into the paraventricular nucleus.
Dimethyl sulfoxide (DMSO) is becoming increasingly popular as a vehicle in studies employing central injections. The aim of the present study was to determine whether the vehicle required for solubilization of substances for central injection [75% DMSO and 25% artificial CSF (aCSF)] would alter the well-characterized stimulatory response to norepinephrine (NE) injected into the paraventricular nucleus (PVN) on short-term food intake. To evaluate its suitability, we compared the effects of repeated unilateral injections of NE dissolved in two different vehicles (100% aCSF or 75% DMSO, 25% aCSF), in separate groups of animals every 48 h over a 30-day period. NE (40 nmol) stimulated food intake by approximately sevenfold compared to either vehicle alone, and the stimulatory effect was similar whether aCSF or 75% DMSO was used as a vehicle. Furthermore, the NE-induced feeding did not vary in magnitude across a series of 13 tests. These results suggest that 75% DMSO is a suitable vehicle for administering NE (and likely other water-insoluble substances)in small volumes of 0.3 microl into specific brain regions.
Blevins
J Ernie
JE
Veterans Administration Medical Center, Omaha, NE 68105, USA.
Stanley
B Glenn
BG
Reidelberger
Roger D
RD
D000818:Animals; D002555:Cerebrospinal Fluid / Q000502:physiology; D004121:Dimethyl Sulfoxide / Q000008:administration & dosage*; D004435:Eating / Q000187:drug effects* / Q000502:physiology; D007276:Injections, Intraventricular; D008297:Male; D009638:Norepinephrine / Q000008:administration & dosage* / Q000134:cerebrospinal fluid; D010286:Paraventricular Hypothalamic Nucleus / Q000187:drug effects* / Q000502:physiology; D014677:Pharmaceutical Vehicles / Q000008:administration & dosage*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012997:Solvents / Q000008:administration & dosage; D013566:Sympathomimetics / Q000008:administration & dosage / Q000134:cerebrospinal fluid
D014677:Pharmaceutical Vehicles; D012997:Solvents; D013566:Sympathomimetics; D009638:Norepinephrine; D004121:Dimethyl Sulfoxide