Table 1.

A Summary of Studies That Examined the Effects of Hydrostatic Pressure on Nucleus Pulposus Cells In Vitro from a Range of Species.

Authors	Animal (Predominate Cell Type)	Pressures (MPa) Range Applied	Summary of Results
			Collagena	Proteoglycanb
Kasra et al. (2003)30	Rabbit (NC)	0.75-3	No change 0.75-2.5 MPa ↓ 3 MPa	Not measured
Hutton et al. (2001)32	Dog (NC)	0.35 and 1	↑ 0.35 MPa ↓ 1 MPa	↓ 0.35 MPa ↑ 1 MPa
Gokorsch et al. (2004)28	Pig (NC)	0.4, 3.4, and 6.0	↑ 0.4 MPa ↓ 6 MPa	↑ 0.4 MPA ↓ 3.4 and 6 MPa
MacLean et al. (2004)31	Rat (NC)	0.2 and 1	No change at 0.2 or 1 MPa	↑ 1 MPa
Purmessur et al. (2013)33	Pig (NC)	0.5-2	No change	↑ PG staining No change in aggrecan gene expression
Wang et al. (2007)29	Rabbit (NC)	0.5 and 1	↑ 0.5 MPa ↑ 1 MPa	↑ 0.5 MPa ↑ 1 MPa
Sowa et al. (2011)27	Rabbit (NC)	0.7, 2, and 4	Not measured	↑ 0.7 MPa No change at 2 or 4 MPa
Neidlinger-Wilke et al. (2006)22	Human (MNP)	0.25 and 2.5	No change	↓ 2.5 MPa
Neidlinger-Wilke et al. (2006)22	Bovine (MNP)	0.25 and 2.5	↑ 0.25 MPa ↓ 2.5 MPa	↑ 0.25 MPa ↓ 2.5 MPa
Ishihara et al. (1996)23	Bovine (MNP)	2.5-10	Not measured	↓ PG with increasing pressure (2-10 MPa)
Le Maitre et al. (2008)25	Human (healthy and degenerate)	0.8-17	No change	↑ Healthy ↓ Degenerate

MNP = mature nucleus pulposus; NC = notochordal; PG = proteoglycan.

^aCollagen measured by gene expression or collagen protein assay

^bProteoglycan measured by aggrecan gene, glycosaminoglycan assay, or radiolabeled proteoglycan synthesis assay.