Journal: The Journal of Neuroscience
Article Title: α2-Adrenergic Agonists Induce Basic Fibroblast Growth Factor Expression in Photoreceptors In Vivo and Ameliorate Light Damage
Figure Lengend Snippet: Induction of bFGF mRNA expression in the retina by xylazine. Total RNA (20 μg/lane) was electrophoresed on a 1% formaldehyde denaturing gel. Northern blot hybridization was performed with 32 P-labeled probes complementary to mRNA encoding bFGF. A major bFGF transcript of 7.0 kb was detected in all blots. Then each blot was stripped and rehybridized with probes for 18s rRNA, which served as a control for RNA loading. Migration of 28s and 18s rRNA was indicated for each blot. A , Xylazine-induced bFGF expression. Animals were injected with either the ketamine–xylazine mixture ( Ket+Xyl ; ketamine, 40 mg/kg; xylazine, 6 mg/kg, i.m.), ketamine alone ( Ket ; 40 mg/kg, i.m.), xylazine alone ( Xyl ; 6 mg/kg, i.m.), or PBS (0.5 ml, i.m.). Control animals were uninjected. Retinas were collected 12 hr after injection. There was a 4.5-fold increase in bFGF signal in retinas from ketamine–xylazine-injected animals and also a 4.5-fold increase in retinas from xylazine-treated animals. No significant change occurred in bFGF mRNA in either ketamine- or PBS-treated retinas. B , Time course of xylazine-induced bFGF expression. Animals were injected with xylazine (6 mg/kg, i.m.), and retinas were collected 12, 24 , and 48 hr after the injection. Expression of bFGF mRNA increased 5.7-fold at 12 hr after xylazine injection, declined to twofold, and returned to the control level by 48 hr. C , Inhibition of xylazine effect by yohimbine. Animals were injected with PBS (0.5 ml, i.m.), xylazine ( Xyl ; 6 mg/kg, i.m.), or yohimbine (5 mg/kg, i.p., 20 min before xylazine) plus xylazine ( Yoh+Xyl ) or yohimbine alone ( Yoh ; 5 mg/kg, i.p.). Retinas were collected 12 hr after injection. There was a significant increase in bFGF expression in xylazine-treated animals. Pretreatment with yohimbine completely blocked the effect of xylazine. No significant change in bFGF expression occurred in either PBS or yohimbine-treated animals.
Article Snippet: Ketamine (Fort Dodge Laboratories, Fort Dodge, IA), xylazine (either from Lloyd Laboratories, Shenandoah, IA, or Sigma, St. Louis, MO), or PBS was injected intramuscularly into the right hind leg.
Techniques: Expressing, Northern Blot, Hybridization, Labeling, Migration, Injection, Inhibition