Research Interests:
Cardiovascular health and disease:
– Regulation of integrated venous function in health and disease (chronic heart failure)
– Myogenic factors controlling venomotor tone
– Sympathetic neurotransmission and adrenergic pathways
– Endothelinergic pathways
– Effects of sex steroids on vascular reactivity
Techniques available in our lab:
– Vascular pressure myography
– High pressure liquid chromato-graphy (HPLC)
– Echocardiography
– Instrumented whole-animal studies
Clinical Pharmacology
– Analgesic use in companion and food producing animals
– Pharmacokinetic studies
– Drug delivery systems
– Drug and analyte assays (HPLC, ELISA, EIA) (non-GLP)
– Clinical trials for regulatory approval of veterinary drugs (GCP)
– Exploratory/Discovery studies (non-GLP)
Links:
Students:
Shawn Veitch
Saad Enouri(Ph.D Candidate)
Afrah Al-Najeer (Ph.D Candidate)
Publications:
1. Enouri S, Monteith G, Johnson RJ. Characterization of myogenic factors in rat mesenteric veins. Am J Physiol Regul Integr Comp Physiol. doi: 10.1152/ajpregu. 00491.2010.
2. McLelland DJ, Barker IK, Crawshaw G, Hinds LA, Spilsbury L, Johnson R. Single dose pharmacokinetics of oxytetracycline and penicillin G in tammar wallabies (Macropus eugenii). J Vet Pharmacol Therap. doi: 10.1111/j. 1365-2885.2010.01216.xp.
3. Washburn K, Johnson R, Clarke C, Anderson K. Distribution of ceftiofur intoMannheimia haemolytica-infected tissue chambers and lung after subcutaneous administration of ceftior crystalline free acid sterile suspension. J Vet Pharmacol Therap 2010, 33 (2): 141-146.
4. Washburn K, Johnson R, Clarke C, Anderson K, Lucas M, Bryson W, Robinson J, Dame K, Hubbard V, Callahan K, Robb E. Penetration of ceftiofur crystalline free acid sterile suspension into sterile versus Mannheimia haemolytica-infected tissue chambers in beef calves after subcutaneous administration in the ear pinna. J Vet Pharm Exp Ther 2005; 28 (3): 247-252.
5. Johnson RJ, Fink GD, Watts, SW, Galligan JJ. Endothelin receptor function in mesenteric veins from deoxycorticosterone acetate-salt hypertensive rats. J Hypertens 2002; 20(4): 665-676.
6. Johnson RJ, Galligan JJ, Fink GD. Effect of an ETB-selective and mixed ETA/B endothelin receptor antagonist on venomotor tone in deoxycorticosterone-salt hypertension. J Hypertension 2001; 19 (3): 1-10.
7. Johnson RJ, Galligan JJ, Fink GD. Factors affecting endothelin-induced venous tone in conscious rats. J Cardiovasc Pharmacol 2001; 37(2): 187-195.
8. Fink GD, Johnson RJ, Galligan JJ. Mechanisms of increased venous smooth muscle tone in deoxycorticosterone acetate-salt hypertension. Hypertension 2000; 35 (1 pt 2): 464-469.
9. Johnson RJ, Black WD, Sigler RE, Baragi V, Gough AW. Evaluation of toxicokinetic variables and histologic appearance of arthropathic changes in juvenile rabbits after oral administration of an investigational fluoroquinolone, PD 117596. Am J Vet Res 2000; 61 (11): 1396-1402.
10. Johnson RJ, Fink GD, Galligan JJ. Mechanisms of endothelin-induced venoconstriction in isolated guinea pig mesentery. J Pharm Exp Ther 1999; 289 (2): 762-767.
11. Gough A, Johnson R, Campbell E, Hall L, Taylor J, Carpenter A, Black WD, Basrur PK, Baragi VM, Sigler R, Metz A. Quinolone arthropathy in immature rabbits treated with fluoroquinolone, PD 117596. Exp Toxic Pathol 1996; 48: 225-232.